21370550 has 24 divisors (see below), whose sum is σ = 39918576. Its totient is φ = 8511840.

The previous prime is 21370549. The next prime is 21370561. The reversal of 21370550 is 5507312.

21370550 = 128² + 129² + ... + 404².

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13079 + ... + 14621.

It is an arithmetic number, because the mean of its divisors is an integer number (1663274).

Almost surely, 2^21370550 is an apocalyptic number.

21370550 is a deficient number, since it is larger than the sum of its proper divisors (18548026).

21370550 is a wasteful number, since it uses less digits than its factorization.

21370550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1832 (or 1827 counting only the distinct ones).

The product of its (nonzero) digits is 1050, while the sum is 23.

The square root of 21370550 is about 4622.8292202936. The cubic root of 21370550 is about 277.5056947672.

Adding to 21370550 its reverse (5507312), we get a palindrome (26877862).

The spelling of 21370550 in words is "twenty-one million, three hundred seventy thousand, five hundred fifty".