21660774 has 8 divisors (see below), whose sum is σ = 43321560. Its totient is φ = 7220256.

The previous prime is 21660761. The next prime is 21660791. The reversal of 21660774 is 47706612.

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

21660774 is an admirable number.

It is a congruent number.

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, 1805059 + ... + 1805070.

It is an arithmetic number, because the mean of its divisors is an integer number (5415195).

Almost surely, 2^21660774 is an apocalyptic number.

21660774 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21660774 is a wasteful number, since it uses less digits than its factorization.

21660774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3610134.

The product of its (nonzero) digits is 14112, while the sum is 33.

The square root of 21660774 is about 4654.1136642759. The cubic root of 21660774 is about 278.7562779525.

The spelling of 21660774 in words is "twenty-one million, six hundred sixty thousand, seven hundred seventy-four".