1251000642651 has 4 divisors (see below), whose sum is σ = 1668000856872. Its totient is φ = 834000428432.

The previous prime is 1251000642641. The next prime is 1251000642659. The reversal of 1251000642651 is 1562460001521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1251000642651 - 2¹⁸ = 1251000380507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1251000642659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208500107106 + ... + 208500107111.

It is an arithmetic number, because the mean of its divisors is an integer number (417000214218).

Almost surely, 2^{1251000642651} is an apocalyptic number.

1251000642651 is a deficient number, since it is larger than the sum of its proper divisors (417000214221).

1251000642651 is an equidigital number, since it uses as much as digits as its factorization.

1251000642651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417000214220.

The product of its (nonzero) digits is 14400, while the sum is 33.

The spelling of 1251000642651 in words is "one trillion, two hundred fifty-one billion, six hundred forty-two thousand, six hundred fifty-one".