161690217772 has 12 divisors (see below), whose sum is σ = 283032429120. Its totient is φ = 80823809456.

The previous prime is 161690217761. The next prime is 161690217839. The reversal of 161690217772 is 277712096161.

It is a super-2 number, since 2×161690217772² (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 3 ways as a sum of consecutive naturals, for example, 5307772 + ... + 5338147.

It is an arithmetic number, because the mean of its divisors is an integer number (23586035760).

Almost surely, 2^161690217772 is an apocalyptic number.

It is an amenable number.

161690217772 is a deficient number, since it is larger than the sum of its proper divisors (121342211348).

161690217772 is a wasteful number, since it uses less digits than its factorization.

161690217772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10649720 (or 10649718 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 49.

The spelling of 161690217772 in words is "one hundred sixty-one billion, six hundred ninety million, two hundred seventeen thousand, seven hundred seventy-two".