20347947 has 12 divisors (see below), whose sum is σ = 29795064. Its totient is φ = 13379040.

The previous prime is 20347909. The next prime is 20347973. The reversal of 20347947 is 74974302.

It is not a de Polignac number, because 20347947 - 2⁶ = 20347883 is a prime.

It is a super-2 number, since 2×20347947² = 828077894229618, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20347907) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14829 + ... + 16142.

It is an arithmetic number, because the mean of its divisors is an integer number (2482922).

Almost surely, 2^20347947 is an apocalyptic number.

20347947 is a deficient number, since it is larger than the sum of its proper divisors (9447117).

20347947 is a wasteful number, since it uses less digits than its factorization.

20347947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31050 (or 31047 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 20347947 is about 4510.8698717653. The cubic root of 20347947 is about 273.0068428024.

The spelling of 20347947 in words is "twenty million, three hundred forty-seven thousand, nine hundred forty-seven".