20431477 has 4 divisors (see below), whose sum is σ = 22288896. Its totient is φ = 18574060.

The previous prime is 20431451. The next prime is 20431547. The reversal of 20431477 is 77413402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20431477 - 2¹⁵ = 20398709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431427) 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, 928693 + ... + 928714.

It is an arithmetic number, because the mean of its divisors is an integer number (5572224).

Almost surely, 2^20431477 is an apocalyptic number.

It is an amenable number.

20431477 is a deficient number, since it is larger than the sum of its proper divisors (1857419).

20431477 is a wasteful number, since it uses less digits than its factorization.

20431477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1857418.

The product of its (nonzero) digits is 4704, while the sum is 28.

The square root of 20431477 is about 4520.1191355981. The cubic root of 20431477 is about 273.3799046497.

Adding to 20431477 its reverse (77413402), we get a palindrome (97844879).

The spelling of 20431477 in words is "twenty million, four hundred thirty-one thousand, four hundred seventy-seven".