161240402 has 4 divisors (see below), whose sum is σ = 241860606. Its totient is φ = 80620200.

The previous prime is 161240399. The next prime is 161240407. The reversal of 161240402 is 204042161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 204042161 = 37 ⋅5514653.

It can be written as a sum of positive squares in only one way, i.e., 101626561 + 59613841 = 10081^2 + 7721^2 .

It is not an unprimeable number, because it can be changed into a prime (161240407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40310099 + ... + 40310102.

Almost surely, 2^161240402 is an apocalyptic number.

161240402 is a deficient number, since it is larger than the sum of its proper divisors (80620204).

161240402 is an equidigital number, since it uses as much as digits as its factorization.

161240402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80620203.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 161240402 is about 12698.0471726955. The cubic root of 161240402 is about 544.2828172768.

Adding to 161240402 its reverse (204042161), we get a palindrome (365282563).

The spelling of 161240402 in words is "one hundred sixty-one million, two hundred forty thousand, four hundred two".