21958497792 has 640 divisors, whose sum is σ = 82887552000. Its totient is φ = 5689958400.

The previous prime is 21958497767. The next prime is 21958497793. The reversal of 21958497792 is 29779485912.

21958497792 is a `hidden beast` number, since 2 + 1 + 9 + 58 + 497 + 7 + 92 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

Its product of digits (22861440) is a multiple of the sum of its prime factors (480).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21958497793) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 52157742 + ... + 52158162.

It is an arithmetic number, because the mean of its divisors is an integer number (129511800).

Almost surely, 2^21958497792 is an apocalyptic number.

21958497792 is a gapful number since it is divisible by the number (22) 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 21958497792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41443776000).

21958497792 is an abundant number, since it is smaller than the sum of its proper divisors (60929054208).

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

21958497792 is an equidigital number, since it uses as much as digits as its factorization.

21958497792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 444 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 63.

The spelling of 21958497792 in words is "twenty-one billion, nine hundred fifty-eight million, four hundred ninety-seven thousand, seven hundred ninety-two".