161621734381 has 8 divisors (see below), whose sum is σ = 164524492800. Its totient is φ = 158740398960.

The previous prime is 161621734363. The next prime is 161621734403. The reversal of 161621734381 is 183437126161.

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 161621734381 - 2¹¹ = 161621732333 is a prime.

It is a super-2 number, since 2×161621734381² (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 (161621734481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5340526 + ... + 5370703.

It is an arithmetic number, because the mean of its divisors is an integer number (20565561600).

Almost surely, 2^161621734381 is an apocalyptic number.

It is an amenable number.

161621734381 is a deficient number, since it is larger than the sum of its proper divisors (2902758419).

161621734381 is a wasteful number, since it uses less digits than its factorization.

161621734381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10711499.

The product of its digits is 145152, while the sum is 43.

The spelling of 161621734381 in words is "one hundred sixty-one billion, six hundred twenty-one million, seven hundred thirty-four thousand, three hundred eighty-one".