166897131261 has 16 divisors (see below), whose sum is σ = 254415168000. Its totient is φ = 95333890608.

The previous prime is 166897131259. The next prime is 166897131337. The reversal of 166897131261 is 162131798661.

It is a happy number.

It is not a de Polignac number, because 166897131261 - 2¹ = 166897131259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166897131221) 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, 1438611 + ... + 1550288.

It is an arithmetic number, because the mean of its divisors is an integer number (15900948000).

Almost surely, 2^166897131261 is an apocalyptic number.

It is an amenable number.

166897131261 is a deficient number, since it is larger than the sum of its proper divisors (87518036739).

166897131261 is a wasteful number, since it uses less digits than its factorization.

166897131261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2991568.

The product of its digits is 653184, while the sum is 51.

The spelling of 166897131261 in words is "one hundred sixty-six billion, eight hundred ninety-seven million, one hundred thirty-one thousand, two hundred sixty-one".