20402947 has 8 divisors (see below), whose sum is σ = 21150800. Its totient is φ = 19665504.

The previous prime is 20402927. The next prime is 20402951. The reversal of 20402947 is 74920402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20402947 - 2²³ = 12014339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20402927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1504 + ... + 6562.

It is an arithmetic number, because the mean of its divisors is an integer number (2643850).

Almost surely, 2^20402947 is an apocalyptic number.

20402947 is a deficient number, since it is larger than the sum of its proper divisors (747853).

20402947 is a wasteful number, since it uses less digits than its factorization.

20402947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5205.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20402947 is about 4516.9621428566. The cubic root of 20402947 is about 273.2525984373.

The spelling of 20402947 in words is "twenty million, four hundred two thousand, nine hundred forty-seven".