721157066 has 16 divisors (see below), whose sum is σ = 1242133440. Its totient is φ = 307601280.

The previous prime is 721157057. The next prime is 721157071. The reversal of 721157066 is 660751127.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119111 + ... + 125018.

It is an arithmetic number, because the mean of its divisors is an integer number (77633340).

Almost surely, 2^721157066 is an apocalyptic number.

721157066 is a deficient number, since it is larger than the sum of its proper divisors (520976374).

721157066 is a wasteful number, since it uses less digits than its factorization.

721157066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244349.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 721157066 is about 26854.3677266846. The cubic root of 721157066 is about 896.7608109686.

The spelling of 721157066 in words is "seven hundred twenty-one million, one hundred fifty-seven thousand, sixty-six".