21479400 has 72 divisors (see below), whose sum is σ = 72141030. Its totient is φ = 5727360.

The previous prime is 21479377. The next prime is 21479407. The reversal of 21479400 is 497412.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 19027044 + 2452356 = 4362^2 + 1566^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21479400² = 922729248720000, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21479407) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4167 + ... + 7766.

Almost surely, 2^21479400 is an apocalyptic number.

21479400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21479400 is an abundant number, since it is smaller than the sum of its proper divisors (50661630).

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

21479400 is a wasteful number, since it uses less digits than its factorization.

21479400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11955 (or 11943 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21479400 is about 4634.5873602728. The cubic root of 21479400 is about 277.9760516264.

The spelling of 21479400 in words is "twenty-one million, four hundred seventy-nine thousand, four hundred".