21357887 has 8 divisors (see below), whose sum is σ = 22040640. Its totient is φ = 20685600.

The previous prime is 21357871. The next prime is 21357901. The reversal of 21357887 is 78875312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21357887 - 2⁴ = 21357871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1637 + ... + 6737.

It is an arithmetic number, because the mean of its divisors is an integer number (2755080).

Almost surely, 2^21357887 is an apocalyptic number.

21357887 is a deficient number, since it is larger than the sum of its proper divisors (682753).

21357887 is an equidigital number, since it uses as much as digits as its factorization.

21357887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5233.

The product of its digits is 94080, while the sum is 41.

The square root of 21357887 is about 4621.4594015311. The cubic root of 21357887 is about 277.4508724546.

The spelling of 21357887 in words is "twenty-one million, three hundred fifty-seven thousand, eight hundred eighty-seven".