321997545 has 32 divisors (see below), whose sum is σ = 585763200. Its totient is φ = 167735232.

The previous prime is 321997537. The next prime is 321997547. The reversal of 321997545 is 545799123.

It is a happy number.

321997545 is a `hidden beast` number, since 3 + 2 + 19 + 97 + 545 = 666.

It is not a de Polignac number, because 321997545 - 2³ = 321997537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 321997545.

It is not an unprimeable number, because it can be changed into a prime (321997547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21930 + ... + 33539.

It is an arithmetic number, because the mean of its divisors is an integer number (18305100).

Almost surely, 2^321997545 is an apocalyptic number.

It is an amenable number.

321997545 is a deficient number, since it is larger than the sum of its proper divisors (263765655).

321997545 is a wasteful number, since it uses less digits than its factorization.

321997545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55526 (or 55520 counting only the distinct ones).

The product of its digits is 340200, while the sum is 45.

The square root of 321997545 is about 17944.2900388954. The cubic root of 321997545 is about 685.4106582664.

The spelling of 321997545 in words is "three hundred twenty-one million, nine hundred ninety-seven thousand, five hundred forty-five".