720902989 has 4 divisors (see below), whose sum is σ = 724930560. Its totient is φ = 716875420.

The previous prime is 720902983. The next prime is 720902993. The reversal of 720902989 is 989209027.

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, and also an emirpimes, since its reverse is a distinct semiprime: 989209027 = 19 ⋅52063633.

It is a cyclic number.

It is not a de Polignac number, because 720902989 - 2³ = 720902981 is a prime.

It is a super-4 number, since 4×720902989⁴ (a number of 37 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720902981) 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, 2013517 + ... + 2013874.

It is an arithmetic number, because the mean of its divisors is an integer number (181232640).

Almost surely, 2^720902989 is an apocalyptic number.

It is an amenable number.

720902989 is a deficient number, since it is larger than the sum of its proper divisors (4027571).

720902989 is a wasteful number, since it uses less digits than its factorization.

720902989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4027570.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 720902989 is about 26849.6366642083. The cubic root of 720902989 is about 896.6554834467.

The spelling of 720902989 in words is "seven hundred twenty million, nine hundred two thousand, nine hundred eighty-nine".