21425633897 has 4 divisors (see below), whose sum is σ = 21881498496. Its totient is φ = 20969769300.

The previous prime is 21425633881. The next prime is 21425633909. The reversal of 21425633897 is 79833652412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21425633897 - 2⁴ = 21425633881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21425639897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227932229 + ... + 227932322.

It is an arithmetic number, because the mean of its divisors is an integer number (5470374624).

Almost surely, 2^21425633897 is an apocalyptic number.

It is an amenable number.

21425633897 is a deficient number, since it is larger than the sum of its proper divisors (455864599).

21425633897 is an equidigital number, since it uses as much as digits as its factorization.

21425633897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455864598.

The product of its digits is 2177280, while the sum is 50.

The spelling of 21425633897 in words is "twenty-one billion, four hundred twenty-five million, six hundred thirty-three thousand, eight hundred ninety-seven".