721861465 has 16 divisors (see below), whose sum is σ = 935298000. Its totient is φ = 531677952.

The previous prime is 721861451. The next prime is 721861477. The reversal of 721861465 is 564168127.

It can be written as a sum of positive squares in 8 ways, for example, as 213043216 + 508818249 = 14596^2 + 22557^2 .

It is not a de Polignac number, because 721861465 - 2¹⁵ = 721828697 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11011 + ... + 39559.

It is an arithmetic number, because the mean of its divisors is an integer number (58456125).

Almost surely, 2^721861465 is an apocalyptic number.

It is an amenable number.

721861465 is a deficient number, since it is larger than the sum of its proper divisors (213436535).

721861465 is a wasteful number, since it uses less digits than its factorization.

721861465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28956.

The product of its digits is 80640, while the sum is 40.

The square root of 721861465 is about 26867.4796919994. The cubic root of 721861465 is about 897.0526899935.

The spelling of 721861465 in words is "seven hundred twenty-one million, eight hundred sixty-one thousand, four hundred sixty-five".