21508952145 has 32 divisors (see below), whose sum is σ = 35613198720. Its totient is φ = 11072087040.

The previous prime is 21508952137. The next prime is 21508952167. The reversal of 21508952145 is 54125980512.

It is not a de Polignac number, because 21508952145 - 2³ = 21508952137 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21508952097 and 21508952106.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1629462 + ... + 1642608.

It is an arithmetic number, because the mean of its divisors is an integer number (1112912460).

Almost surely, 2^21508952145 is an apocalyptic number.

It is an amenable number.

21508952145 is a deficient number, since it is larger than the sum of its proper divisors (14104246575).

21508952145 is a wasteful number, since it uses less digits than its factorization.

21508952145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16945.

The product of its (nonzero) digits is 144000, while the sum is 42.

The spelling of 21508952145 in words is "twenty-one billion, five hundred eight million, nine hundred fifty-two thousand, one hundred forty-five".