638651525 has 12 divisors (see below), whose sum is σ = 792261792. Its totient is φ = 510705840.

The previous prime is 638651411. The next prime is 638651539. The reversal of 638651525 is 525156836.

It is not a de Polignac number, because 638651525 - 2¹⁶ = 638585989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84554 + ... + 91796.

It is an arithmetic number, because the mean of its divisors is an integer number (66021816).

Almost surely, 2^638651525 is an apocalyptic number.

It is an amenable number.

638651525 is a deficient number, since it is larger than the sum of its proper divisors (153610267).

638651525 is a wasteful number, since it uses less digits than its factorization.

638651525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10780 (or 10775 counting only the distinct ones).

The product of its digits is 216000, while the sum is 41.

The square root of 638651525 is about 25271.5556505728. Note that the first 3 decimals coincide. The cubic root of 638651525 is about 861.1682001539.

The spelling of 638651525 in words is "six hundred thirty-eight million, six hundred fifty-one thousand, five hundred twenty-five".