161642621455 has 16 divisors (see below), whose sum is σ = 221839833600. Its totient is φ = 110761392672.

The previous prime is 161642621443. The next prime is 161642621461. The reversal of 161642621455 is 554126246161.

It is not a de Polignac number, because 161642621455 - 2¹¹ = 161642619407 is a prime.

It is a super-2 number, since 2×161642621455² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1601629 + ... + 1699558.

It is an arithmetic number, because the mean of its divisors is an integer number (13864989600).

Almost surely, 2^161642621455 is an apocalyptic number.

161642621455 is a deficient number, since it is larger than the sum of its proper divisors (60197212145).

161642621455 is a wasteful number, since it uses less digits than its factorization.

161642621455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3302598.

The product of its digits is 345600, while the sum is 43.

The spelling of 161642621455 in words is "one hundred sixty-one billion, six hundred forty-two million, six hundred twenty-one thousand, four hundred fifty-five".