20697556 has 12 divisors (see below), whose sum is σ = 39513600. Its totient is φ = 9407960.

The previous prime is 20697511. The next prime is 20697559. The reversal of 20697556 is 65579602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20697559) 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, 235156 + ... + 235243.

It is an arithmetic number, because the mean of its divisors is an integer number (3292800).

Almost surely, 2^20697556 is an apocalyptic number.

It is an amenable number.

20697556 is a deficient number, since it is larger than the sum of its proper divisors (18816044).

20697556 is a wasteful number, since it uses less digits than its factorization.

20697556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470414 (or 470412 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 40.

The square root of 20697556 is about 4549.4566708564. The cubic root of 20697556 is about 274.5615315671.

The spelling of 20697556 in words is "twenty million, six hundred ninety-seven thousand, five hundred fifty-six".