21046900 has 72 divisors (see below), whose sum is σ = 52871616. Its totient is φ = 7123200.

The previous prime is 21046897. The next prime is 21046903. The reversal of 21046900 is 964012.

It is an interprime number because it is at equal distance from previous prime (21046897) and next prime (21046903).

It is a super-2 number, since 2×21046900² = 885943999220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21046903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74760 + ... + 75040.

It is an arithmetic number, because the mean of its divisors is an integer number (734328).

Almost surely, 2^21046900 is an apocalyptic number.

21046900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21046900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26435808).

21046900 is an abundant number, since it is smaller than the sum of its proper divisors (31824716).

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

21046900 is a wasteful number, since it uses less digits than its factorization.

21046900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409 (or 402 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21046900 is about 4587.6900505592. The cubic root of 21046900 is about 276.0976515062.

The spelling of 21046900 in words is "twenty-one million, forty-six thousand, nine hundred".