20634009 has 12 divisors (see below), whose sum is σ = 30241008. Its totient is φ = 12505240.

The previous prime is 20634001. The next prime is 20634017. The reversal of 20634009 is 90043602.

20634009 = T₂₈₆ + T₂₈₇ + ... + T₅₂₇.

It is an interprime number because it is at equal distance from previous prime (20634001) and next prime (20634017).

It is not a de Polignac number, because 20634009 - 2³ = 20634001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20634009.

It is not an unprimeable number, because it can be changed into a prime (20634001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28059 + ... + 28784.

It is an arithmetic number, because the mean of its divisors is an integer number (2520084).

Almost surely, 2^20634009 is an apocalyptic number.

It is an amenable number.

20634009 is a deficient number, since it is larger than the sum of its proper divisors (9606999).

20634009 is a wasteful number, since it uses less digits than its factorization.

20634009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56868 (or 56857 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 20634009 is about 4542.4672811150. The cubic root of 20634009 is about 274.2802512010.

The spelling of 20634009 in words is "twenty million, six hundred thirty-four thousand, nine".