1625264138 has 4 divisors (see below), whose sum is σ = 2437896210. Its totient is φ = 812632068.

The previous prime is 1625264129. The next prime is 1625264143. The reversal of 1625264138 is 8314625261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1093823329 + 531440809 = 33073^2 + 23053^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406316033 + ... + 406316036.

Almost surely, 2^1625264138 is an apocalyptic number.

1625264138 is a deficient number, since it is larger than the sum of its proper divisors (812632072).

1625264138 is an equidigital number, since it uses as much as digits as its factorization.

1625264138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812632071.

The product of its digits is 69120, while the sum is 38.

The square root of 1625264138 is about 40314.5648370412. The cubic root of 1625264138 is about 1175.7310405982.

Adding to 1625264138 its reverse (8314625261), we get a palindrome (9939889399).

The spelling of 1625264138 in words is "one billion, six hundred twenty-five million, two hundred sixty-four thousand, one hundred thirty-eight".