20492657 has 4 divisors (see below), whose sum is σ = 20512500. Its totient is φ = 20472816.

The previous prime is 20492653. The next prime is 20492669. The reversal of 20492657 is 75629402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17673616 + 2819041 = 4204^2 + 1679^2 .

It is a cyclic number.

It is not a de Polignac number, because 20492657 - 2² = 20492653 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20492651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8282 + ... + 10467.

It is an arithmetic number, because the mean of its divisors is an integer number (5128125).

Almost surely, 2^20492657 is an apocalyptic number.

It is an amenable number.

20492657 is a deficient number, since it is larger than the sum of its proper divisors (19843).

20492657 is a wasteful number, since it uses less digits than its factorization.

20492657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19842.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 20492657 is about 4526.8815977447. The cubic root of 20492657 is about 273.6525022716.

The spelling of 20492657 in words is "twenty million, four hundred ninety-two thousand, six hundred fifty-seven".