21479290 has 16 divisors (see below), whose sum is σ = 44186112. Its totient is φ = 7364304.

The previous prime is 21479281. The next prime is 21479303. The reversal of 21479290 is 9297412.

It is a happy number.

It is a super-2 number, since 2×21479290² = 922719797808200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153354 + ... + 153493.

It is an arithmetic number, because the mean of its divisors is an integer number (2761632).

Almost surely, 2^21479290 is an apocalyptic number.

21479290 is an abundant number, since it is smaller than the sum of its proper divisors (22706822).

21479290 is a wasteful number, since it uses less digits than its factorization.

21479290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306861.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 21479290 is about 4634.5754929659. The cubic root of 21479290 is about 277.9755771033.

The spelling of 21479290 in words is "twenty-one million, four hundred seventy-nine thousand, two hundred ninety".