21006552260 has 12 divisors (see below), whose sum is σ = 44113759788. Its totient is φ = 8402620896.

The previous prime is 21006552223. The next prime is 21006552269. The reversal of 21006552260 is 6225560012.

It can be written as a sum of positive squares in 2 ways, for example, as 15989096704 + 5017455556 = 126448^2 + 70834^2 .

It is a super-2 number, since 2×21006552260² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21006552269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525163787 + ... + 525163826.

It is an arithmetic number, because the mean of its divisors is an integer number (3676146649).

Almost surely, 2^21006552260 is an apocalyptic number.

21006552260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21006552260 is an abundant number, since it is smaller than the sum of its proper divisors (23107207528).

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

21006552260 is a wasteful number, since it uses less digits than its factorization.

21006552260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050327622 (or 1050327620 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The spelling of 21006552260 in words is "twenty-one billion, six million, five hundred fifty-two thousand, two hundred sixty".