21700408 has 16 divisors (see below), whose sum is σ = 42457680. Its totient is φ = 10378368.

The previous prime is 21700391. The next prime is 21700409. The reversal of 21700408 is 80400712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58785 + ... + 59152.

It is an arithmetic number, because the mean of its divisors is an integer number (2653605).

Almost surely, 2^21700408 is an apocalyptic number.

It is an amenable number.

21700408 is a deficient number, since it is larger than the sum of its proper divisors (20757272).

21700408 is a wasteful number, since it uses less digits than its factorization.

21700408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117966 (or 117962 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 21700408 is about 4658.3696718917. The cubic root of 21700408 is about 278.9261933125.

The spelling of 21700408 in words is "twenty-one million, seven hundred thousand, four hundred eight".