21067400 has 24 divisors (see below), whose sum is σ = 48982170. Its totient is φ = 8426880.

The previous prime is 21067391. The next prime is 21067433. The reversal of 21067400 is 476012.

It can be written as a sum of positive squares in 3 ways, for example, as 20232004 + 835396 = 4498^2 + 914^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52469 + ... + 52868.

Almost surely, 2^21067400 is an apocalyptic number.

21067400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21067400 is an abundant number, since it is smaller than the sum of its proper divisors (27914770).

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

21067400 is a wasteful number, since it uses less digits than its factorization.

21067400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105353 (or 105344 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21067400 is about 4589.9237466433. The cubic root of 21067400 is about 276.1872635189.

The spelling of 21067400 in words is "twenty-one million, sixty-seven thousand, four hundred".