1251728763 has 4 divisors (see below), whose sum is σ = 1668971688. Its totient is φ = 834485840.

The previous prime is 1251728749. The next prime is 1251728767. The reversal of 1251728763 is 3678271521.

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 1251728763 - 2⁹ = 1251728251 is a prime.

It is a super-2 number, since 2×1251728763² = 3133649792243020338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1251728767) 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, 208621458 + ... + 208621463.

It is an arithmetic number, because the mean of its divisors is an integer number (417242922).

Almost surely, 2^1251728763 is an apocalyptic number.

1251728763 is a deficient number, since it is larger than the sum of its proper divisors (417242925).

1251728763 is an equidigital number, since it uses as much as digits as its factorization.

1251728763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417242924.

The product of its digits is 141120, while the sum is 42.

The square root of 1251728763 is about 35379.7790128768. The cubic root of 1251728763 is about 1077.7137171873.

The spelling of 1251728763 in words is "one billion, two hundred fifty-one million, seven hundred twenty-eight thousand, seven hundred sixty-three".