21292720794 has 24 divisors (see below), whose sum is σ = 46136911392. Its totient is φ = 7097160840.

The previous prime is 21292720793. The next prime is 21292720843. The reversal of 21292720794 is 49702729212.

It is a happy number.

It is a super-2 number, since 2×21292720794² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21292720793) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 593179 + ... + 628049.

It is an arithmetic number, because the mean of its divisors is an integer number (1922371308).

Almost surely, 2^21292720794 is an apocalyptic number.

21292720794 is an abundant number, since it is smaller than the sum of its proper divisors (24844190598).

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

21292720794 is a wasteful number, since it uses less digits than its factorization.

21292720794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68802 (or 68799 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The spelling of 21292720794 in words is "twenty-one billion, two hundred ninety-two million, seven hundred twenty thousand, seven hundred ninety-four".