21489364066 has 16 divisors (see below), whose sum is σ = 33364490040. Its totient is φ = 10368288000.

The previous prime is 21489364049. The next prime is 21489364069. The reversal of 21489364066 is 66046398412.

It can be written as a sum of positive squares in 4 ways, for example, as 17586738225 + 3902625841 = 132615^2 + 62471^2 .

It is a super-2 number, since 2×21489364066² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21489364069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1185 + ... + 207316.

Almost surely, 2^21489364066 is an apocalyptic number.

21489364066 is a deficient number, since it is larger than the sum of its proper divisors (11875125974).

21489364066 is a wasteful number, since it uses less digits than its factorization.

21489364066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210309.

The product of its (nonzero) digits is 1492992, while the sum is 49.

The spelling of 21489364066 in words is "twenty-one billion, four hundred eighty-nine million, three hundred sixty-four thousand, sixty-six".