721455 has 16 divisors (see below), whose sum is σ = 1319424. Its totient is φ = 329760.

The previous prime is 721451. The next prime is 721481. The reversal of 721455 is 554127.

It is not a de Polignac number, because 721455 - 2² = 721451 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3331 + ... + 3540.

It is an arithmetic number, because the mean of its divisors is an integer number (82464).

2⁷²¹⁴⁵⁵ is an apocalyptic number.

721455 is a deficient number, since it is larger than the sum of its proper divisors (597969).

721455 is a wasteful number, since it uses less digits than its factorization.

721455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6886.

The product of its digits is 1400, while the sum is 24.

The square root of 721455 is about 849.3850716842. The cubic root of 721455 is about 89.6884287884.

It can be divided in two parts, 721 and 455, that added together give a triangular number (1176 = T₄₈).

The spelling of 721455 in words is "seven hundred twenty-one thousand, four hundred fifty-five".