21930147 has 6 divisors (see below), whose sum is σ = 31676892. Its totient is φ = 14620092.

The previous prime is 21930143. The next prime is 21930157. The reversal of 21930147 is 74103912.

It is not a de Polignac number, because 21930147 - 2² = 21930143 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21930147.

It is not an unprimeable number, because it can be changed into a prime (21930143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1218333 + ... + 1218350.

It is an arithmetic number, because the mean of its divisors is an integer number (5279482).

Almost surely, 2^21930147 is an apocalyptic number.

21930147 is a deficient number, since it is larger than the sum of its proper divisors (9746745).

21930147 is a wasteful number, since it uses less digits than its factorization.

21930147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2436689 (or 2436686 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21930147 is about 4682.9634848032. The cubic root of 21930147 is about 279.9070567368.

The spelling of 21930147 in words is "twenty-one million, nine hundred thirty thousand, one hundred forty-seven".