721965 has 8 divisors (see below), whose sum is σ = 1155168. Its totient is φ = 385040.

The previous prime is 721961. The next prime is 721979. The reversal of 721965 is 569127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721965 - 2² = 721961 is a prime.

It is a super-2 number, since 2×721965² = 1042466922450, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24051 + ... + 24080.

It is an arithmetic number, because the mean of its divisors is an integer number (144396).

2⁷²¹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

721965 is a deficient number, since it is larger than the sum of its proper divisors (433203).

721965 is a wasteful number, since it uses less digits than its factorization.

721965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48139.

The product of its digits is 3780, while the sum is 30.

The square root of 721965 is about 849.6852358374. The cubic root of 721965 is about 89.7095575374.

The spelling of 721965 in words is "seven hundred twenty-one thousand, nine hundred sixty-five".