21697034580 has 324 divisors, whose sum is σ = 73385174772. Its totient is φ = 5186488320.

The previous prime is 21697034561. The next prime is 21697034663. The reversal of 21697034580 is 8543079612.

21697034580 is a `hidden beast` number, since 2 + 1 + 69 + 7 + 0 + 3 + 4 + 580 = 666.

It can be written as a sum of positive squares in 18 ways, for example, as 13355500356 + 8341534224 = 115566^2 + 91332^2 .

It is a super-2 number, since 2×21697034580² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 41644720 + ... + 41645240.

It is an arithmetic number, because the mean of its divisors is an integer number (226497453).

It is a 1-persistent number, because it is pandigital, but 2⋅21697034580 = 43394069160 is not.

Almost surely, 2^21697034580 is an apocalyptic number.

21697034580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21697034580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36692587386).

21697034580 is an abundant number, since it is smaller than the sum of its proper divisors (51688140192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21697034580 is a wasteful number, since it uses less digits than its factorization.

21697034580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636 (or 581 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21697034580 in words is "twenty-one billion, six hundred ninety-seven million, thirty-four thousand, five hundred eighty".