166120721953 has 8 divisors (see below), whose sum is σ = 171855852480. Its totient is φ = 160386046800.

The previous prime is 166120721947. The next prime is 166120721959. The reversal of 166120721953 is 359127021661.

It is an interprime number because it is at equal distance from previous prime (166120721947) and next prime (166120721959).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166120721953 - 2³³ = 157530787361 is a prime.

It is a super-2 number, since 2×166120721953² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166120721959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 735978 + ... + 934828.

It is an arithmetic number, because the mean of its divisors is an integer number (21481981560).

Almost surely, 2^166120721953 is an apocalyptic number.

It is an amenable number.

166120721953 is a deficient number, since it is larger than the sum of its proper divisors (5735130527).

166120721953 is a wasteful number, since it uses less digits than its factorization.

166120721953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227687.

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 166120721953 in words is "one hundred sixty-six billion, one hundred twenty million, seven hundred twenty-one thousand, nine hundred fifty-three".