161764402 has 4 divisors (see below), whose sum is σ = 242646606. Its totient is φ = 80882200.

The previous prime is 161764391. The next prime is 161764441. The reversal of 161764402 is 204467161.

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., 104019601 + 57744801 = 10199^2 + 7599^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40441099 + ... + 40441102.

Almost surely, 2^161764402 is an apocalyptic number.

161764402 is a deficient number, since it is larger than the sum of its proper divisors (80882204).

161764402 is an equidigital number, since it uses as much as digits as its factorization.

161764402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80882203.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 161764402 is about 12718.6635304186. The cubic root of 161764402 is about 544.8717842200.

The spelling of 161764402 in words is "one hundred sixty-one million, seven hundred sixty-four thousand, four hundred two".