161621734705 has 32 divisors (see below), whose sum is σ = 206132428800. Its totient is φ = 121231690752.

The previous prime is 161621734663. The next prime is 161621734753. The reversal of 161621734705 is 507437126161.

It is a cyclic number.

It is not a de Polignac number, because 161621734705 - 2³³ = 153031800113 is a prime.

It is a super-2 number, since 2×161621734705² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26583856 + ... + 26589934.

It is an arithmetic number, because the mean of its divisors is an integer number (6441638400).

Almost surely, 2^161621734705 is an apocalyptic number.

It is an amenable number.

161621734705 is a deficient number, since it is larger than the sum of its proper divisors (44510694095).

161621734705 is a wasteful number, since it uses less digits than its factorization.

161621734705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7233.

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 161621734705 in words is "one hundred sixty-one billion, six hundred twenty-one million, seven hundred thirty-four thousand, seven hundred five".