720155391 has 8 divisors (see below), whose sum is σ = 966566784. Its totient is φ = 476923800.

The previous prime is 720155341. The next prime is 720155407. The reversal of 720155391 is 193551027.

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

It is not a de Polignac number, because 720155391 - 2¹⁹ = 719631103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720155321) 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, 794421 + ... + 795326.

It is an arithmetic number, because the mean of its divisors is an integer number (120820848).

Almost surely, 2^720155391 is an apocalyptic number.

720155391 is a deficient number, since it is larger than the sum of its proper divisors (246411393).

720155391 is a wasteful number, since it uses less digits than its factorization.

720155391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589901.

The product of its (nonzero) digits is 9450, while the sum is 33.

The square root of 720155391 is about 26835.7111141106. The cubic root of 720155391 is about 896.3454233738.

The spelling of 720155391 in words is "seven hundred twenty million, one hundred fifty-five thousand, three hundred ninety-one".