321561061 has 4 divisors (see below), whose sum is σ = 322149472. Its totient is φ = 320972652.

The previous prime is 321561011. The next prime is 321561067. The reversal of 321561061 is 160165123.

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: 160165123 = 23 ⋅6963701.

It is a cyclic number.

It is not a de Polignac number, because 321561061 - 2⁹ = 321560549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321561067) 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, 293385 + ... + 294478.

It is an arithmetic number, because the mean of its divisors is an integer number (80537368).

Almost surely, 2^321561061 is an apocalyptic number.

It is an amenable number.

321561061 is a deficient number, since it is larger than the sum of its proper divisors (588411).

321561061 is an equidigital number, since it uses as much as digits as its factorization.

321561061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588410.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 321561061 is about 17932.1237169500. The cubic root of 321561061 is about 685.1008152539.

The spelling of 321561061 in words is "three hundred twenty-one million, five hundred sixty-one thousand, sixty-one".