720431989 has 4 divisors (see below), whose sum is σ = 721553056. Its totient is φ = 719310924.

The previous prime is 720431941. The next prime is 720431993. The reversal of 720431989 is 989134027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 720431989 - 2¹³ = 720423797 is a prime.

It is a super-2 number, since 2×720431989² = 1038044501548992242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720431689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 559569 + ... + 560854.

It is an arithmetic number, because the mean of its divisors is an integer number (180388264).

Almost surely, 2^720431989 is an apocalyptic number.

It is an amenable number.

720431989 is a deficient number, since it is larger than the sum of its proper divisors (1121067).

720431989 is a wasteful number, since it uses less digits than its factorization.

720431989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121066.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 720431989 is about 26840.8641626904. The cubic root of 720431989 is about 896.4601650994.

It can be divided in two parts, 7204 and 31989, that added together give a palindrome (39193).

The spelling of 720431989 in words is "seven hundred twenty million, four hundred thirty-one thousand, nine hundred eighty-nine".