21475400 has 24 divisors (see below), whose sum is σ = 49930770. Its totient is φ = 8590080.

The previous prime is 21475393. The next prime is 21475409. The reversal of 21475400 is 457412.

It can be written as a sum of positive squares in 3 ways, for example, as 19695844 + 1779556 = 4438^2 + 1334^2 .

It is a super-2 number, since 2×21475400² = 922385610320000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21475409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53489 + ... + 53888.

Almost surely, 2^21475400 is an apocalyptic number.

21475400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21475400 is an abundant number, since it is smaller than the sum of its proper divisors (28455370).

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

21475400 is a wasteful number, since it uses less digits than its factorization.

21475400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107393 (or 107384 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21475400 is about 4634.1558023010. The cubic root of 21475400 is about 277.9587951973.

The spelling of 21475400 in words is "twenty-one million, four hundred seventy-five thousand, four hundred".