21906878202 has 24 divisors (see below), whose sum is σ = 51779894400. Its totient is φ = 6638447880.

The previous prime is 21906878179. The next prime is 21906878207. The reversal of 21906878202 is 20287860912.

It is a super-2 number, since 2×21906878202² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21906878207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55320202 + ... + 55320597.

It is an arithmetic number, because the mean of its divisors is an integer number (2157495600).

Almost surely, 2^21906878202 is an apocalyptic number.

21906878202 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21906878202 is an abundant number, since it is smaller than the sum of its proper divisors (29873016198).

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

21906878202 is a wasteful number, since it uses less digits than its factorization.

21906878202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110640818 (or 110640815 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 21906878202 in words is "twenty-one billion, nine hundred six million, eight hundred seventy-eight thousand, two hundred two".