161674221520 has 40 divisors (see below), whose sum is σ = 429591504384. Its totient is φ = 55431161472.

The previous prime is 161674221509. The next prime is 161674221523. The reversal of 161674221520 is 25122476161.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×161674221520² (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 161674221520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161674221523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144351424 + ... + 144352543.

Almost surely, 2^161674221520 is an apocalyptic number.

161674221520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161674221520 is an abundant number, since it is smaller than the sum of its proper divisors (267917282864).

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

161674221520 is a wasteful number, since it uses less digits than its factorization.

161674221520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288703987 (or 288703981 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

Adding to 161674221520 its reverse (25122476161), we get a palindrome (186796697681).

The spelling of 161674221520 in words is "one hundred sixty-one billion, six hundred seventy-four million, two hundred twenty-one thousand, five hundred twenty".