21490774 has 4 divisors (see below), whose sum is σ = 32236164. Its totient is φ = 10745386.

The previous prime is 21490759. The next prime is 21490783. The reversal of 21490774 is 47709412.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5372692 + ... + 5372695.

It is an arithmetic number, because the mean of its divisors is an integer number (8059041).

Almost surely, 2^21490774 is an apocalyptic number.

21490774 is a deficient number, since it is larger than the sum of its proper divisors (10745390).

21490774 is a wasteful number, since it uses less digits than its factorization.

21490774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10745389.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 21490774 is about 4635.8142758312. The cubic root of 21490774 is about 278.0251085787.

The spelling of 21490774 in words is "twenty-one million, four hundred ninety thousand, seven hundred seventy-four".