20625916509 has 12 divisors (see below), whose sum is σ = 32501444352. Its totient is φ = 12500555400.

The previous prime is 20625916501. The next prime is 20625916543. The reversal of 20625916509 is 90561952602.

It is a happy number.

20625916509 is a `hidden beast` number, since 2 + 0 + 6 + 2 + 591 + 6 + 50 + 9 = 666.

It is not a de Polignac number, because 20625916509 - 2³ = 20625916501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20625916501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104171197 + ... + 104171394.

It is an arithmetic number, because the mean of its divisors is an integer number (2708453696).

Almost surely, 2^20625916509 is an apocalyptic number.

It is an amenable number.

20625916509 is a deficient number, since it is larger than the sum of its proper divisors (11875527843).

20625916509 is a wasteful number, since it uses less digits than its factorization.

20625916509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208342608 (or 208342605 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 45.

The spelling of 20625916509 in words is "twenty billion, six hundred twenty-five million, nine hundred sixteen thousand, five hundred nine".