21930417 has 6 divisors (see below), whose sum is σ = 31677282. Its totient is φ = 14620272.

The previous prime is 21930413. The next prime is 21930421. The reversal of 21930417 is 71403912.

21930417 is a `hidden beast` number, since 219 + 30 + 417 = 666.

It is an interprime number because it is at equal distance from previous prime (21930413) and next prime (21930421).

It can be written as a sum of positive squares in only one way, i.e., 20711601 + 1218816 = 4551^2 + 1104^2 .

It is not a de Polignac number, because 21930417 - 2² = 21930413 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21930413) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1218348 + ... + 1218365.

It is an arithmetic number, because the mean of its divisors is an integer number (5279547).

Almost surely, 2^21930417 is an apocalyptic number.

It is an amenable number.

21930417 is a deficient number, since it is larger than the sum of its proper divisors (9746865).

21930417 is a wasteful number, since it uses less digits than its factorization.

21930417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2436719 (or 2436716 counting only the distinct ones).

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

The square root of 21930417 is about 4682.9923126138. The cubic root of 21930417 is about 279.9082054538.

The spelling of 21930417 in words is "twenty-one million, nine hundred thirty thousand, four hundred seventeen".