21364860 has 48 divisors (see below), whose sum is σ = 65261952. Its totient is φ = 5179200.

The previous prime is 21364853. The next prime is 21364877. The reversal of 21364860 is 6846312.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15526 + ... + 16845.

It is an arithmetic number, because the mean of its divisors is an integer number (1359624).

Almost surely, 2^21364860 is an apocalyptic number.

21364860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21364860 is an abundant number, since it is smaller than the sum of its proper divisors (43897092).

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

21364860 is a wasteful number, since it uses less digits than its factorization.

21364860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32394 (or 32392 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 21364860 is about 4622.2137553341. The cubic root of 21364860 is about 277.4810635564.

It can be divided in two parts, 2136 and 4860, that added together give a palindrome (6996).

The spelling of 21364860 in words is "twenty-one million, three hundred sixty-four thousand, eight hundred sixty".