21696860 has 24 divisors (see below), whose sum is σ = 47962320. Its totient is φ = 8221824.

The previous prime is 21696859. The next prime is 21696877. The reversal of 21696860 is 6869612.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28169 + ... + 28928.

It is an arithmetic number, because the mean of its divisors is an integer number (1998430).

Almost surely, 2^21696860 is an apocalyptic number.

21696860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21696860 is an abundant number, since it is smaller than the sum of its proper divisors (26265460).

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

21696860 is a wasteful number, since it uses less digits than its factorization.

21696860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57125 (or 57123 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 21696860 is about 4657.9888363971. The cubic root of 21696860 is about 278.9109910780.

The spelling of 21696860 in words is "twenty-one million, six hundred ninety-six thousand, eight hundred sixty".