21962857644 has 192 divisors, whose sum is σ = 73770009600. Its totient is φ = 5487492096.

The previous prime is 21962857613. The next prime is 21962857717. The reversal of 21962857644 is 44675826912.

21962857644 is a `hidden beast` number, since 2 + 1 + 9 + 6 + 28 + 576 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 127924 + ... + 245540.

It is an arithmetic number, because the mean of its divisors is an integer number (384218800).

Almost surely, 2^21962857644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21962857644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36885004800).

21962857644 is an abundant number, since it is smaller than the sum of its proper divisors (51807151956).

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

21962857644 is a wasteful number, since it uses less digits than its factorization.

21962857644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117669 (or 117661 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The spelling of 21962857644 in words is "twenty-one billion, nine hundred sixty-two million, eight hundred fifty-seven thousand, six hundred forty-four".