20472761 has 4 divisors (see below), whose sum is σ = 20490624. Its totient is φ = 20454900.

The previous prime is 20472757. The next prime is 20472763. The reversal of 20472761 is 16727402.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16727402 = 2 ⋅8363701.

It is a cyclic number.

It is not a de Polignac number, because 20472761 - 2² = 20472757 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20472763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7085 + ... + 9546.

It is an arithmetic number, because the mean of its divisors is an integer number (5122656).

Almost surely, 2^20472761 is an apocalyptic number.

20472761 is the 2024-th centered decagonal number.

It is an amenable number.

20472761 is a deficient number, since it is larger than the sum of its proper divisors (17863).

20472761 is a wasteful number, since it uses less digits than its factorization.

20472761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17862.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 20472761 is about 4524.6835248446. The cubic root of 20472761 is about 273.5639119510.

The spelling of 20472761 in words is "twenty million, four hundred seventy-two thousand, seven hundred sixty-one".