161661147220 has 24 divisors (see below), whose sum is σ = 339630971904. Its totient is φ = 64637304096.

The previous prime is 161661147217. The next prime is 161661147239. The reversal of 161661147220 is 22741166161.

It is a super-2 number, since 2×161661147220² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161661147220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1648324 + ... + 1743643.

It is an arithmetic number, because the mean of its divisors is an integer number (14151290496).

Almost surely, 2^161661147220 is an apocalyptic number.

161661147220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161661147220 is an abundant number, since it is smaller than the sum of its proper divisors (177969824684).

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

161661147220 is a wasteful number, since it uses less digits than its factorization.

161661147220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3394359 (or 3394357 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The spelling of 161661147220 in words is "one hundred sixty-one billion, six hundred sixty-one million, one hundred forty-seven thousand, two hundred twenty".