21577394 has 8 divisors (see below), whose sum is σ = 32410908. Its totient is φ = 10773760.

The previous prime is 21577373. The next prime is 21577429. The reversal of 21577394 is 49377512.

It can be written as a sum of positive squares in 2 ways, for example, as 21576025 + 1369 = 4645^2 + 37^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5567 + ... + 8610.

Almost surely, 2^21577394 is an apocalyptic number.

21577394 is a deficient number, since it is larger than the sum of its proper divisors (10833514).

21577394 is a wasteful number, since it uses less digits than its factorization.

21577394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14940.

The product of its digits is 52920, while the sum is 38.

The square root of 21577394 is about 4645.1473604182. The cubic root of 21577394 is about 278.3981407729.

The spelling of 21577394 in words is "twenty-one million, five hundred seventy-seven thousand, three hundred ninety-four".