721407 has 8 divisors (see below), whose sum is σ = 967680. Its totient is φ = 478040.

The previous prime is 721397. The next prime is 721439. The reversal of 721407 is 704127.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721207) 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, 57 + ... + 1202.

It is an arithmetic number, because the mean of its divisors is an integer number (120960).

2⁷²¹⁴⁰⁷ is an apocalyptic number.

721407 is a deficient number, since it is larger than the sum of its proper divisors (246273).

721407 is a wasteful number, since it uses less digits than its factorization.

721407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1453.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 721407 is about 849.3568154786. The cubic root of 721407 is about 89.6864396877.

It can be divided in two parts, 721 and 407, that added together give a triangular number (1128 = T₄₇).

The spelling of 721407 in words is "seven hundred twenty-one thousand, four hundred seven", and thus it is an iban number.