1672276721 has 2 divisors, whose sum is σ = 1672276722. Its totient is φ = 1672276720.

The previous prime is 1672276699. The next prime is 1672276729. The reversal of 1672276721 is 1276722761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 846519025 + 825757696 = 29095^2 + 28736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1672276721 is a prime.

It is not a weakly prime, because it can be changed into another prime (1672276729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 836138360 + 836138361.

It is an arithmetic number, because the mean of its divisors is an integer number (836138361).

Almost surely, 2^1672276721 is an apocalyptic number.

It is an amenable number.

1672276721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1672276721 is an equidigital number, since it uses as much as digits as its factorization.

1672276721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784, while the sum is 41.

The square root of 1672276721 is about 40893.4801771627. The cubic root of 1672276721 is about 1186.9599026604.

The spelling of 1672276721 in words is "one billion, six hundred seventy-two million, two hundred seventy-six thousand, seven hundred twenty-one".