21190394 has 8 divisors (see below), whose sum is σ = 31961748. Its totient is φ = 10536480.

The previous prime is 21190349. The next prime is 21190409. The reversal of 21190394 is 49309112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17749369 + 3441025 = 4213^2 + 1855^2 .

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, 28907 + ... + 29630.

Almost surely, 2^21190394 is an apocalyptic number.

21190394 is a deficient number, since it is larger than the sum of its proper divisors (10771354).

21190394 is a wasteful number, since it uses less digits than its factorization.

21190394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58720.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 21190394 is about 4603.3025101551. The cubic root of 21190394 is about 276.7236923790.

The spelling of 21190394 in words is "twenty-one million, one hundred ninety thousand, three hundred ninety-four".