20958973644 has 288 divisors, whose sum is σ = 62736844800. Its totient is φ = 5408363520.

The previous prime is 20958973597. The next prime is 20958973657. The reversal of 20958973644 is 44637985902.

It is a Harshad number since it is a multiple of its sum of digits (57).

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, 25281822 + ... + 25282650.

Almost surely, 2^20958973644 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 20958973644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31368422400).

20958973644 is an abundant number, since it is smaller than the sum of its proper divisors (41777871156).

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

20958973644 is a wasteful number, since it uses less digits than its factorization.

20958973644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 973 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 57.

The spelling of 20958973644 in words is "twenty billion, nine hundred fifty-eight million, nine hundred seventy-three thousand, six hundred forty-four".