721516 has 6 divisors (see below), whose sum is σ = 1262660. Its totient is φ = 360756.

The previous prime is 721499. The next prime is 721529. The reversal of 721516 is 615127.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90186 + ... + 90193.

2⁷²¹⁵¹⁶ is an apocalyptic number.

It is an amenable number.

721516 is a deficient number, since it is larger than the sum of its proper divisors (541144).

721516 is a wasteful number, since it uses less digits than its factorization.

721516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180383 (or 180381 counting only the distinct ones).

The product of its digits is 420, while the sum is 22.

The square root of 721516 is about 849.4209792559. The cubic root of 721516 is about 89.6909564767.

It can be divided in two parts, 7215 and 16, that multiplied together give a triangular number (115440 = T₄₈₀).

The spelling of 721516 in words is "seven hundred twenty-one thousand, five hundred sixteen".