213169201661 has 16 divisors (see below), whose sum is σ = 235456471488. Its totient is φ = 191735164800.

The previous prime is 213169201649. The next prime is 213169201699. The reversal of 213169201661 is 166102961312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213169201661 is a prime.

It is a super-2 number, since 2×213169201661² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213169201061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 185690 + ... + 678836.

It is an arithmetic number, because the mean of its divisors is an integer number (14716029468).

Almost surely, 2^213169201661 is an apocalyptic number.

It is an amenable number.

213169201661 is a deficient number, since it is larger than the sum of its proper divisors (22287269827).

213169201661 is a wasteful number, since it uses less digits than its factorization.

213169201661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494012.

The product of its (nonzero) digits is 23328, while the sum is 38.

The spelling of 213169201661 in words is "two hundred thirteen billion, one hundred sixty-nine million, two hundred one thousand, six hundred sixty-one".