21172650212 has 24 divisors (see below), whose sum is σ = 42374169600. Its totient is φ = 9067806720.

The previous prime is 21172650179. The next prime is 21172650217. The reversal of 21172650212 is 21205627112.

It is a happy number.

It is a super-2 number, since 2×21172650212² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21172650217) 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, 215837 + ... + 298212.

It is an arithmetic number, because the mean of its divisors is an integer number (1765590400).

Almost surely, 2^21172650212 is an apocalyptic number.

It is an amenable number.

21172650212 is an abundant number, since it is smaller than the sum of its proper divisors (21201519388).

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

21172650212 is a wasteful number, since it uses less digits than its factorization.

21172650212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515531 (or 515529 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The spelling of 21172650212 in words is "twenty-one billion, one hundred seventy-two million, six hundred fifty thousand, two hundred twelve".