21251122770 has 16 divisors (see below), whose sum is σ = 51002694720. Its totient is φ = 5666966064.

The previous prime is 21251122769. The next prime is 21251122807. The reversal of 21251122770 is 7722115212.

It is a super-2 number, since 2×21251122770² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 708370759 = 21251122770 / (2 + 1 + 2 + 5 + 1 + 1 + 2 + 2 + 7 + 7 + 0).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354185350 + ... + 354185409.

It is an arithmetic number, because the mean of its divisors is an integer number (3187668420).

Almost surely, 2^21251122770 is an apocalyptic number.

21251122770 is an abundant number, since it is smaller than the sum of its proper divisors (29751571950).

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

21251122770 is a wasteful number, since it uses less digits than its factorization.

21251122770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708370769.

The product of its (nonzero) digits is 3920, while the sum is 30.

Adding to 21251122770 its reverse (7722115212), we get a palindrome (28973237982).

The spelling of 21251122770 in words is "twenty-one billion, two hundred fifty-one million, one hundred twenty-two thousand, seven hundred seventy".