21672541440 has 720 divisors, whose sum is σ = 87469595136. Its totient is φ = 5076172800.

The previous prime is 21672541403. The next prime is 21672541483. The reversal of 21672541440 is 4414527612.

21672541440 is a `hidden beast` number, since 2 + 1 + 6 + 72 + 541 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21672541395 and 21672541404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 35354574 + ... + 35355186.

Almost surely, 2^21672541440 is an apocalyptic number.

21672541440 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 21672541440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43734797568).

21672541440 is an abundant number, since it is smaller than the sum of its proper divisors (65797053696).

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

21672541440 is a wasteful number, since it uses less digits than its factorization.

21672541440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 665 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 21672541440 in words is "twenty-one billion, six hundred seventy-two million, five hundred forty-one thousand, four hundred forty".