20472987 has 4 divisors (see below), whose sum is σ = 27297320. Its totient is φ = 13648656.

The previous prime is 20472973. The next prime is 20472997. The reversal of 20472987 is 78927402.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20472987 - 2⁴ = 20472971 is a prime.

It is a super-3 number, since 3×20472987³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20472997) 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, 3412162 + ... + 3412167.

It is an arithmetic number, because the mean of its divisors is an integer number (6824330).

Almost surely, 2^20472987 is an apocalyptic number.

20472987 is a deficient number, since it is larger than the sum of its proper divisors (6824333).

20472987 is an equidigital number, since it uses as much as digits as its factorization.

20472987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6824332.

The product of its (nonzero) digits is 56448, while the sum is 39.

The square root of 20472987 is about 4524.7084988980. The cubic root of 20472987 is about 273.5649185766.

The spelling of 20472987 in words is "twenty million, four hundred seventy-two thousand, nine hundred eighty-seven".