21397300 has 18 divisors (see below), whose sum is σ = 46432358. Its totient is φ = 8558880.

The previous prime is 21397297. The next prime is 21397301. The reversal of 21397300 is 379312.

It can be written as a sum of positive squares in 3 ways, for example, as 6697744 + 14699556 = 2588^2 + 3834^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21397301) 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, 106887 + ... + 107086.

Almost surely, 2^21397300 is an apocalyptic number.

21397300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21397300 is an abundant number, since it is smaller than the sum of its proper divisors (25035058).

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

21397300 is a wasteful number, since it uses less digits than its factorization.

21397300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213987 (or 213980 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 21397300 is about 4625.7215653344. The cubic root of 21397300 is about 277.6214332046.

The spelling of 21397300 in words is "twenty-one million, three hundred ninety-seven thousand, three hundred".