161521449 has 4 divisors (see below), whose sum is σ = 215361936. Its totient is φ = 107680964.

The previous prime is 161521447. The next prime is 161521499. The reversal of 161521449 is 944125161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161521449 - 2¹ = 161521447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161521447) 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 in 3 ways as a sum of consecutive naturals, for example, 26920239 + ... + 26920244.

It is an arithmetic number, because the mean of its divisors is an integer number (53840484).

Almost surely, 2^161521449 is an apocalyptic number.

It is an amenable number.

161521449 is a deficient number, since it is larger than the sum of its proper divisors (53840487).

161521449 is an equidigital number, since it uses as much as digits as its factorization.

161521449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53840486.

The product of its digits is 8640, while the sum is 33.

The square root of 161521449 is about 12709.1088987387. The cubic root of 161521449 is about 544.5988676389.

The spelling of 161521449 in words is "one hundred sixty-one million, five hundred twenty-one thousand, four hundred forty-nine".