720690 has 16 divisors (see below), whose sum is σ = 1729728. Its totient is φ = 192176.

The previous prime is 720683. The next prime is 720697. The reversal of 720690 is 96027.

720690 = T₁₅₆ + T₁₅₇ + ... + T₂₀₀.

It is an interprime number because it is at equal distance from previous prime (720683) and next prime (720697).

It is a super-2 number, since 2×720690² = 1038788152200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 720690.

It is not an unprimeable number, because it can be changed into a prime (720697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11982 + ... + 12041.

It is an arithmetic number, because the mean of its divisors is an integer number (108108).

2⁷²⁰⁶⁹⁰ is an apocalyptic number.

720690 is an abundant number, since it is smaller than the sum of its proper divisors (1009038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

720690 is a wasteful number, since it uses less digits than its factorization.

720690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24033.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 720690 is about 848.9346264584. The cubic root of 720690 is about 89.6567169869.

The spelling of 720690 in words is "seven hundred twenty thousand, six hundred ninety".