21172450460 has 24 divisors (see below), whose sum is σ = 50813881440. Its totient is φ = 7259125824.

The previous prime is 21172450459. The next prime is 21172450469. The reversal of 21172450460 is 6405427112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21172450469) 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, 75615755 + ... + 75616034.

It is an arithmetic number, because the mean of its divisors is an integer number (2117245060).

Almost surely, 2^21172450460 is an apocalyptic number.

21172450460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21172450460 is an abundant number, since it is smaller than the sum of its proper divisors (29641430980).

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

21172450460 is a wasteful number, since it uses less digits than its factorization.

21172450460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151231805 (or 151231803 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

Adding to 21172450460 its reverse (6405427112), we get a palindrome (27577877572).

The spelling of 21172450460 in words is "twenty-one billion, one hundred seventy-two million, four hundred fifty thousand, four hundred sixty".