161221469 has 16 divisors (see below), whose sum is σ = 173166000. Its totient is φ = 149796864.

The previous prime is 161221409. The next prime is 161221477. The reversal of 161221469 is 964122161.

161221469 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 2788900 + 158432569 = 1670^2 + 12587^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161221469 is a prime.

It is a super-2 number, since 2×161221469² = 51984724133035922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161221409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103307 + ... + 104855.

It is an arithmetic number, because the mean of its divisors is an integer number (10822875).

Almost surely, 2^161221469 is an apocalyptic number.

It is an amenable number.

161221469 is a deficient number, since it is larger than the sum of its proper divisors (11944531).

161221469 is a wasteful number, since it uses less digits than its factorization.

161221469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712.

The product of its digits is 5184, while the sum is 32.

The square root of 161221469 is about 12697.3016424751. The cubic root of 161221469 is about 544.2615130424.

The spelling of 161221469 in words is "one hundred sixty-one million, two hundred twenty-one thousand, four hundred sixty-nine".