321979569661 has 32 divisors (see below), whose sum is σ = 339657403392. Its totient is φ = 304819200000.

The previous prime is 321979569589. The next prime is 321979569671. The reversal of 321979569661 is 166965979123.

It is a happy number.

It is a 7-Lehmer number, since φ(321979569661) divides (321979569661-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 321979569661 - 2¹³ = 321979561469 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321979569593 and 321979569602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321979569671) 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, 502307901 + ... + 502308541.

It is an arithmetic number, because the mean of its divisors is an integer number (10614293856).

Almost surely, 2^321979569661 is an apocalyptic number.

321979569661 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

321979569661 is the 253764-th centered decagonal number.

It is an amenable number.

321979569661 is a deficient number, since it is larger than the sum of its proper divisors (17677833731).

321979569661 is a wasteful number, since it uses less digits than its factorization.

321979569661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1765.

The product of its digits is 33067440, while the sum is 64.

The spelling of 321979569661 in words is "three hundred twenty-one billion, nine hundred seventy-nine million, five hundred sixty-nine thousand, six hundred sixty-one".