20639375 has 10 divisors (see below), whose sum is σ = 25791744. Its totient is φ = 16511000.

The previous prime is 20639351. The next prime is 20639383. The reversal of 20639375 is 57393602.

It is not a de Polignac number, because 20639375 - 2²² = 16445071 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 9 ways as a sum of consecutive naturals, for example, 15887 + ... + 17136.

Almost surely, 2^20639375 is an apocalyptic number.

20639375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20639375 is a deficient number, since it is larger than the sum of its proper divisors (5152369).

20639375 is an frugal number, since it uses more digits than its factorization.

20639375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33043 (or 33028 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 35.

The square root of 20639375 is about 4543.0578908924. The cubic root of 20639375 is about 274.3040252248.

The spelling of 20639375 in words is "twenty million, six hundred thirty-nine thousand, three hundred seventy-five".