161019421 has 2 divisors, whose sum is σ = 161019422. Its totient is φ = 161019420.

The previous prime is 161019377. The next prime is 161019431. The reversal of 161019421 is 124910161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133864900 + 27154521 = 11570^2 + 5211^2 .

It is a cyclic number.

It is not a de Polignac number, because 161019421 - 2⁷ = 161019293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161019431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80509710 + 80509711.

It is an arithmetic number, because the mean of its divisors is an integer number (80509711).

Almost surely, 2^161019421 is an apocalyptic number.

It is an amenable number.

161019421 is a deficient number, since it is larger than the sum of its proper divisors (1).

161019421 is an equidigital number, since it uses as much as digits as its factorization.

161019421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 161019421 is about 12689.3428119820. The cubic root of 161019421 is about 544.0340559075.

Adding to 161019421 its reverse (124910161), we get a palindrome (285929582).

The spelling of 161019421 in words is "one hundred sixty-one million, nineteen thousand, four hundred twenty-one".