21113690 has 16 divisors (see below), whose sum is σ = 40928328. Its totient is φ = 7795776.

The previous prime is 21113689. The next prime is 21113707. The reversal of 21113690 is 9631112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19598329 + 1515361 = 4427^2 + 1231^2 .

It is a super-2 number, since 2×21113690² = 891575810832200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81077 + ... + 81336.

Almost surely, 2^21113690 is an apocalyptic number.

21113690 is a deficient number, since it is larger than the sum of its proper divisors (19814638).

21113690 is a wasteful number, since it uses less digits than its factorization.

21113690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162433.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 21113690 is about 4594.9635471895. The cubic root of 21113690 is about 276.3893981942.

The spelling of 21113690 in words is "twenty-one million, one hundred thirteen thousand, six hundred ninety".