20634657 has 8 divisors (see below), whose sum is σ = 28709184. Its totient is φ = 13158288.

The previous prime is 20634643. The next prime is 20634697. The reversal of 20634657 is 75643602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20634657 - 2¹⁰ = 20633633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20634697) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149458 + ... + 149595.

It is an arithmetic number, because the mean of its divisors is an integer number (3588648).

Almost surely, 2^20634657 is an apocalyptic number.

It is an amenable number.

20634657 is a deficient number, since it is larger than the sum of its proper divisors (8074527).

20634657 is a wasteful number, since it uses less digits than its factorization.

20634657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299079.

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 20634657 is about 4542.5386074309. The cubic root of 20634657 is about 274.2831223791.

It can be divided in two parts, 206346 and 57, that added together give a triangular number (206403 = T₆₄₂).

The spelling of 20634657 in words is "twenty million, six hundred thirty-four thousand, six hundred fifty-seven".