161690045801 has 8 divisors (see below), whose sum is σ = 162581490120. Its totient is φ = 160800213888.

The previous prime is 161690045791. The next prime is 161690045813. The reversal of 161690045801 is 108540096161.

It can be written as a sum of positive squares in 4 ways, for example, as 103861820176 + 57828225625 = 322276^2 + 240475^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161690045801 is a prime.

It is a super-2 number, since 2×161690045801² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161690045821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201716 + ... + 603381.

It is an arithmetic number, because the mean of its divisors is an integer number (20322686265).

Almost surely, 2^161690045801 is an apocalyptic number.

It is an amenable number.

161690045801 is a deficient number, since it is larger than the sum of its proper divisors (891444319).

161690045801 is an equidigital number, since it uses as much as digits as its factorization.

161690045801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806203.

The product of its (nonzero) digits is 51840, while the sum is 41.

The spelling of 161690045801 in words is "one hundred sixty-one billion, six hundred ninety million, forty-five thousand, eight hundred one".