21487850 has 24 divisors (see below), whose sum is σ = 40110528. Its totient is φ = 8564400.

The previous prime is 21487783. The next prime is 21487891. The reversal of 21487850 is 5878412.

It is a self number, because there is not a number n which added to its sum of digits gives 21487850.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17765 + ... + 18935.

It is an arithmetic number, because the mean of its divisors is an integer number (1671272).

Almost surely, 2^21487850 is an apocalyptic number.

21487850 is a deficient number, since it is larger than the sum of its proper divisors (18622678).

21487850 is a wasteful number, since it uses less digits than its factorization.

21487850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1550 (or 1545 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 21487850 is about 4635.4988944018. The cubic root of 21487850 is about 278.0124987911.

The spelling of 21487850 in words is "twenty-one million, four hundred eighty-seven thousand, eight hundred fifty".