161555723157 has 8 divisors (see below), whose sum is σ = 215637525376. Its totient is φ = 107588868192.

The previous prime is 161555723137. The next prime is 161555723177. The reversal of 161555723157 is 751327555161.

It is an interprime number because it is at equal distance from previous prime (161555723137) and next prime (161555723177).

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

It is not a de Polignac number, because 161555723157 - 2¹⁹ = 161555198869 is a prime.

It is a super-2 number, since 2×161555723157² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161555723107) 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, 28733533 + ... + 28739154.

It is an arithmetic number, because the mean of its divisors is an integer number (26954690672).

Almost surely, 2^161555723157 is an apocalyptic number.

It is an amenable number.

161555723157 is a deficient number, since it is larger than the sum of its proper divisors (54081802219).

161555723157 is an equidigital number, since it uses as much as digits as its factorization.

161555723157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57473627.

The product of its digits is 1102500, while the sum is 48.

The spelling of 161555723157 in words is "one hundred sixty-one billion, five hundred fifty-five million, seven hundred twenty-three thousand, one hundred fifty-seven".