21134977920 has 768 divisors, whose sum is σ = 88256520000. Its totient is φ = 4765630464.

The previous prime is 21134977901. The next prime is 21134978023. The reversal of 21134977920 is 2977943112.

21134977920 is a `hidden beast` number, since 211 + 349 + 7 + 7 + 92 + 0 = 666.

It is a super-3 number, since 3×21134977920³ (a number of 32 digits) contains 333 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 95 ways as a sum of consecutive naturals, for example, 92292366 + ... + 92292594.

Almost surely, 2^21134977920 is an apocalyptic number.

21134977920 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 21134977920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44128260000).

21134977920 is an abundant number, since it is smaller than the sum of its proper divisors (67121542080).

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

21134977920 is a wasteful number, since it uses less digits than its factorization.

21134977920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 355 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The spelling of 21134977920 in words is "twenty-one billion, one hundred thirty-four million, nine hundred seventy-seven thousand, nine hundred twenty".