20477691 has 20 divisors (see below), whose sum is σ = 32944912. Its totient is φ = 12601008.

The previous prime is 20477647. The next prime is 20477693. The reversal of 20477691 is 19677402.

20477691 = T₂₈₃ + T₂₈₄ + ... + T₅₂₅.

It is a happy number.

It is not a de Polignac number, because 20477691 - 2¹⁰ = 20476667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20477693) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8671 + ... + 10776.

Almost surely, 2^20477691 is an apocalyptic number.

20477691 is a deficient number, since it is larger than the sum of its proper divisors (12467221).

20477691 is a wasteful number, since it uses less digits than its factorization.

20477691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19472 (or 19463 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 20477691 is about 4525.2282815345. The cubic root of 20477691 is about 273.5858689608.

The spelling of 20477691 in words is "twenty million, four hundred seventy-seven thousand, six hundred ninety-one".