21930394 has 8 divisors (see below), whose sum is σ = 32930100. Its totient is φ = 10953696.

The previous prime is 21930383. The next prime is 21930413. The reversal of 21930394 is 49303912.

It can be written as a sum of positive squares in 2 ways, for example, as 15705369 + 6225025 = 3963^2 + 2495^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3129 + ... + 7324.

Almost surely, 2^21930394 is an apocalyptic number.

21930394 is a deficient number, since it is larger than the sum of its proper divisors (10999706).

21930394 is a wasteful number, since it uses less digits than its factorization.

21930394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11504.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 21930394 is about 4682.9898569183. The cubic root of 21930394 is about 279.9081076005.

The spelling of 21930394 in words is "twenty-one million, nine hundred thirty thousand, three hundred ninety-four".