20528137538 has 16 divisors (see below), whose sum is σ = 30935909880. Its totient is φ = 10216194816.

The previous prime is 20528137489. The next prime is 20528137549. The reversal of 20528137538 is 83573182502.

It can be written as a sum of positive squares in 4 ways, for example, as 16776207529 + 3751930009 = 129523^2 + 61253^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3043706 + ... + 3050442.

Almost surely, 2^20528137538 is an apocalyptic number.

20528137538 is a deficient number, since it is larger than the sum of its proper divisors (10407772342).

20528137538 is a wasteful number, since it uses less digits than its factorization.

20528137538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13621.

The product of its (nonzero) digits is 403200, while the sum is 44.

The spelling of 20528137538 in words is "twenty billion, five hundred twenty-eight million, one hundred thirty-seven thousand, five hundred thirty-eight".