1251673641 has 15 divisors (see below), whose sum is σ = 1870259853. Its totient is φ = 834236820.

The previous prime is 1251673609. The next prime is 1251673667. The reversal of 1251673641 is 1463761521.

The square root of 1251673641 is 35379.

It is a perfect power (a square), and thus also a powerful number.

1251673641 is a `hidden beast` number, since 1 + 2 + 5 + 1 + 6 + 7 + 3 + 641 = 666.

It is not a de Polignac number, because 1251673641 - 2⁵ = 1251673609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1251673596 and 1251673605.

It is not an unprimeable number, because it can be changed into a prime (1251673441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 316446 + ... + 320376.

Almost surely, 2^1251673641 is an apocalyptic number.

1251673641 is the 35379-th square number.

1251673641 is the 17690-th centered octagonal number.

It is an amenable number.

1251673641 is a deficient number, since it is larger than the sum of its proper divisors (618586212).

1251673641 is an frugal number, since it uses more digits than its factorization.

1251673641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7874 (or 3934 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The cubic root of 1251673641 is about 1077.6978973044.

Multiplying 1251673641 by its sum of digits (36), we get a square (45060251076 = 212274²).

The spelling of 1251673641 in words is "one billion, two hundred fifty-one million, six hundred seventy-three thousand, six hundred forty-one".