320487561 has 12 divisors (see below), whose sum is σ = 464950980. Its totient is φ = 212724000.

The previous prime is 320487551. The next prime is 320487617. The reversal of 320487561 is 165784023.

It can be written as a sum of positive squares in 2 ways, for example, as 258566400 + 61921161 = 16080^2 + 7869^2 .

It is not a de Polignac number, because 320487561 - 2²¹ = 318390409 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (320487511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75690 + ... + 79811.

It is an arithmetic number, because the mean of its divisors is an integer number (38745915).

Almost surely, 2^320487561 is an apocalyptic number.

It is an amenable number.

320487561 is a deficient number, since it is larger than the sum of its proper divisors (144463419).

320487561 is a wasteful number, since it uses less digits than its factorization.

320487561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155736 (or 155733 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 320487561 is about 17902.1663772852. The cubic root of 320487561 is about 684.3375847188.

The spelling of 320487561 in words is "three hundred twenty million, four hundred eighty-seven thousand, five hundred sixty-one".