161611556166004 has 72 divisors (see below), whose sum is σ = 350293675213440. Its totient is φ = 64823676390144.

The previous prime is 161611556166001. The next prime is 161611556166007. The reversal of 161611556166004 is 400661655116161.

It is an interprime number because it is at equal distance from previous prime (161611556166001) and next prime (161611556166007).

It is a super-2 number, since 2×161611556166004² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161611556166001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134886444 + ... + 136079299.

It is an arithmetic number, because the mean of its divisors is an integer number (4865189933520).

Almost surely, 2^{161611556166004} is an apocalyptic number.

161611556166004 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

161611556166004 is an abundant number, since it is smaller than the sum of its proper divisors (188682119047436).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161611556166004 is a wasteful number, since it uses less digits than its factorization.

161611556166004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270965957 (or 270965948 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 49.

The spelling of 161611556166004 in words is "one hundred sixty-one trillion, six hundred eleven billion, five hundred fifty-six million, one hundred sixty-six thousand, four".