161693862394 has 4 divisors (see below), whose sum is σ = 242540793594. Its totient is φ = 80846931196.

The previous prime is 161693862371. The next prime is 161693862397. The reversal of 161693862394 is 493268396161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 104014635169 + 57679227225 = 322513^2 + 240165^2 .

It is a super-2 number, since 2×161693862394² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (161693862397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40423465597 + ... + 40423465600.

Almost surely, 2^161693862394 is an apocalyptic number.

161693862394 is a deficient number, since it is larger than the sum of its proper divisors (80846931200).

161693862394 is an equidigital number, since it uses as much as digits as its factorization.

161693862394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80846931199.

The product of its digits is 10077696, while the sum is 58.

The spelling of 161693862394 in words is "one hundred sixty-one billion, six hundred ninety-three million, eight hundred sixty-two thousand, three hundred ninety-four".