1251561222 has 24 divisors (see below), whose sum is σ = 2717667576. Its totient is φ = 416271456.

The previous prime is 1251561211. The next prime is 1251561247. The reversal of 1251561222 is 2221651521.

1251561222 is a `hidden beast` number, since 1 + 25 + 1 + 5 + 612 + 22 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67848 + ... + 84299.

It is an arithmetic number, because the mean of its divisors is an integer number (113236149).

Almost surely, 2^1251561222 is an apocalyptic number.

1251561222 is an abundant number, since it is smaller than the sum of its proper divisors (1466106354).

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

1251561222 is a wasteful number, since it uses less digits than its factorization.

1251561222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152612 (or 152609 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 1251561222 is about 35377.4111828438. The cubic root of 1251561222 is about 1077.6656318790.

It can be divided in two parts, 12515 and 61222, that added together give a palindrome (73737).

The spelling of 1251561222 in words is "one billion, two hundred fifty-one million, five hundred sixty-one thousand, two hundred twenty-two".