1251221164 has 6 divisors (see below), whose sum is σ = 2189637044. Its totient is φ = 625610580.

The previous prime is 1251221129. The next prime is 1251221239. The reversal of 1251221164 is 4611221521.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156402642 + ... + 156402649.

Almost surely, 2^1251221164 is an apocalyptic number.

It is an amenable number.

1251221164 is a deficient number, since it is larger than the sum of its proper divisors (938415880).

1251221164 is a wasteful number, since it uses less digits than its factorization.

1251221164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312805295 (or 312805293 counting only the distinct ones).

The product of its digits is 960, while the sum is 25.

The square root of 1251221164 is about 35372.6047104253. The cubic root of 1251221164 is about 1077.5680199235.

Adding to 1251221164 its reverse (4611221521), we get a palindrome (5862442685).

The spelling of 1251221164 in words is "one billion, two hundred fifty-one million, two hundred twenty-one thousand, one hundred sixty-four".