21358783080 has 160 divisors (see below), whose sum is σ = 72530405640. Its totient is φ = 5636874240.

The previous prime is 21358783021. The next prime is 21358783099. The reversal of 21358783080 is 8038785312.

It can be written as a sum of positive squares in 4 ways, for example, as 20751554916 + 607228164 = 144054^2 + 24642^2 .

It is a super-2 number, since 2×21358783080² (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 an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 280300 + ... + 348260.

Almost surely, 2^21358783080 is an apocalyptic number.

21358783080 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 21358783080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36265202820).

21358783080 is an abundant number, since it is smaller than the sum of its proper divisors (51171622560).

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

21358783080 is a wasteful number, since it uses less digits than its factorization.

21358783080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68081 (or 68068 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 21358783080 in words is "twenty-one billion, three hundred fifty-eight million, seven hundred eighty-three thousand, eighty".