721674474375949 has 2 divisors, whose sum is σ = 721674474375950. Its totient is φ = 721674474375948.

The previous prime is 721674474375937. The next prime is 721674474375971. The reversal of 721674474375949 is 949573474476127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 362538545798025 + 359135928577924 = 19040445^2 + 18950882^2 .

It is a cyclic number.

It is not a de Polignac number, because 721674474375949 - 2⁵ = 721674474375917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721674474373949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360837237187974 + 360837237187975.

It is an arithmetic number, because the mean of its divisors is an integer number (360837237187975).

Almost surely, 2^{721674474375949} is an apocalyptic number.

It is an amenable number.

721674474375949 is a deficient number, since it is larger than the sum of its proper divisors (1).

721674474375949 is an equidigital number, since it uses as much as digits as its factorization.

721674474375949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8961684480, while the sum is 79.

The spelling of 721674474375949 in words is "seven hundred twenty-one trillion, six hundred seventy-four billion, four hundred seventy-four million, three hundred seventy-five thousand, nine hundred forty-nine".