21380610 has 16 divisors (see below), whose sum is σ = 51313536. Its totient is φ = 5701488.

The previous prime is 21380603. The next prime is 21380621. The reversal of 21380610 is 1608312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 356314 + ... + 356373.

It is an arithmetic number, because the mean of its divisors is an integer number (3207096).

Almost surely, 2^21380610 is an apocalyptic number.

21380610 is an abundant number, since it is smaller than the sum of its proper divisors (29932926).

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

21380610 is a wasteful number, since it uses less digits than its factorization.

21380610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712697.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21380610 is about 4623.9171705384. The cubic root of 21380610 is about 277.5492323980.

Adding to 21380610 its reverse (1608312), we get a palindrome (22988922).

The spelling of 21380610 in words is "twenty-one million, three hundred eighty thousand, six hundred ten".