21012364 has 6 divisors (see below), whose sum is σ = 36771644. Its totient is φ = 10506180.

The previous prime is 21012359. The next prime is 21012367. The reversal of 21012364 is 46321012.

It is not an unprimeable number, because it can be changed into a prime (21012367) by changing a digit.

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 as a sum of consecutive naturals, namely, 2626542 + ... + 2626549.

Almost surely, 2^21012364 is an apocalyptic number.

It is an amenable number.

21012364 is a deficient number, since it is larger than the sum of its proper divisors (15759280).

21012364 is a wasteful number, since it uses less digits than its factorization.

21012364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253095 (or 5253093 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21012364 is about 4583.9245194484. The cubic root of 21012364 is about 275.9465519972.

Adding to 21012364 its reverse (46321012), we get a palindrome (67333376).

It can be divided in two parts, 2101 and 2364, that added together give a triangular number (4465 = T₉₄).

The spelling of 21012364 in words is "twenty-one million, twelve thousand, three hundred sixty-four".