21345610 has 96 divisors (see below), whose sum is σ = 48263040. Its totient is φ = 6737280.

The previous prime is 21345593. The next prime is 21345619. The reversal of 21345610 is 1654312.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21345619) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361761 + ... + 361819.

It is an arithmetic number, because the mean of its divisors is an integer number (502740).

Almost surely, 2^21345610 is an apocalyptic number.

21345610 is an abundant number, since it is smaller than the sum of its proper divisors (26917430).

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

21345610 is a wasteful number, since it uses less digits than its factorization.

21345610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21345610 is about 4620.1309505251. The cubic root of 21345610 is about 277.3977005711.

Adding to 21345610 its reverse (1654312), we get a palindrome (22999922).

It can be divided in two parts, 2134 and 5610, that added together give a square (7744 = 88²).

The spelling of 21345610 in words is "twenty-one million, three hundred forty-five thousand, six hundred ten".