21206465425 has 24 divisors (see below), whose sum is σ = 26473752000. Its totient is φ = 16850702400.

The previous prime is 21206465419. The next prime is 21206465437. The reversal of 21206465425 is 52456460212.

It is a happy number.

It is not a de Polignac number, because 21206465425 - 2⁷ = 21206465297 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6481540 + ... + 6484810.

It is an arithmetic number, because the mean of its divisors is an integer number (1103073000).

Almost surely, 2^21206465425 is an apocalyptic number.

21206465425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21206465425 is a deficient number, since it is larger than the sum of its proper divisors (5267286575).

21206465425 is a wasteful number, since it uses less digits than its factorization.

21206465425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4953 (or 4948 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 37.

The spelling of 21206465425 in words is "twenty-one billion, two hundred six million, four hundred sixty-five thousand, four hundred twenty-five".