21023138738 has 32 divisors (see below), whose sum is σ = 36515422080. Its totient is φ = 8891372160.

The previous prime is 21023138651. The next prime is 21023138749. The reversal of 21023138738 is 83783132012.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 635528 + ... + 667788.

It is an arithmetic number, because the mean of its divisors is an integer number (1141106940).

Almost surely, 2^21023138738 is an apocalyptic number.

21023138738 is a deficient number, since it is larger than the sum of its proper divisors (15492283342).

21023138738 is a wasteful number, since it uses less digits than its factorization.

21023138738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32882.

The product of its (nonzero) digits is 48384, while the sum is 38.

The spelling of 21023138738 in words is "twenty-one billion, twenty-three million, one hundred thirty-eight thousand, seven hundred thirty-eight".