21350660 has 24 divisors (see below), whose sum is σ = 44966040. Its totient is φ = 8515584.

The previous prime is 21350633. The next prime is 21350677. The reversal of 21350660 is 6605312.

It can be written as a sum of positive squares in 4 ways, for example, as 264196 + 21086464 = 514^2 + 4592^2 .

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, 6596 + ... + 9284.

It is an arithmetic number, because the mean of its divisors is an integer number (1873585).

Almost surely, 2^21350660 is an apocalyptic number.

21350660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21350660 is an abundant number, since it is smaller than the sum of its proper divisors (23615380).

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

21350660 is a wasteful number, since it uses less digits than its factorization.

21350660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3095 (or 3093 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 21350660 is about 4620.6774395104. The cubic root of 21350660 is about 277.4195746697.

Adding to 21350660 its reverse (6605312), we get a palindrome (27955972).

The spelling of 21350660 in words is "twenty-one million, three hundred fifty thousand, six hundred sixty".