20697057 has 18 divisors (see below), whose sum is σ = 30904146. Its totient is φ = 13347360.

The previous prime is 20697049. The next prime is 20697071. The reversal of 20697057 is 75079602.

It can be written as a sum of positive squares in only one way, i.e., 11840481 + 8856576 = 3441^2 + 2976^2 .

It is not a de Polignac number, because 20697057 - 2³ = 20697049 is a prime.

It is a super-2 number, since 2×20697057² = 856736336922498, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20697077) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7453 + ... + 9845.

It is an arithmetic number, because the mean of its divisors is an integer number (1716897).

Almost surely, 2^20697057 is an apocalyptic number.

It is an amenable number.

20697057 is a deficient number, since it is larger than the sum of its proper divisors (10207089).

20697057 is a wasteful number, since it uses less digits than its factorization.

20697057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2461 (or 2427 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The square root of 20697057 is about 4549.4018288122. The cubic root of 20697057 is about 274.5593250698.

The spelling of 20697057 in words is "twenty million, six hundred ninety-seven thousand, fifty-seven".