161978702 has 4 divisors (see below), whose sum is σ = 242968056. Its totient is φ = 80989350.

The previous prime is 161978699. The next prime is 161978723. The reversal of 161978702 is 207879161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 207879161 = 7 ⋅29697023.

It is a self number, because there is not a number n which added to its sum of digits gives 161978702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40494674 + ... + 40494677.

It is an arithmetic number, because the mean of its divisors is an integer number (60742014).

Almost surely, 2^161978702 is an apocalyptic number.

161978702 is a deficient number, since it is larger than the sum of its proper divisors (80989354).

161978702 is an equidigital number, since it uses as much as digits as its factorization.

161978702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80989353.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 161978702 is about 12727.0853694002. The cubic root of 161978702 is about 545.1122872753.

The spelling of 161978702 in words is "one hundred sixty-one million, nine hundred seventy-eight thousand, seven hundred two".