161561013 has 16 divisors (see below), whose sum is σ = 232393536. Its totient is φ = 99457280.

The previous prime is 161561011. The next prime is 161561017. The reversal of 161561013 is 310165161.

161561013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 161561013 - 2¹ = 161561011 is a prime.

It is a super-3 number, since 3×161561013³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161561011) 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, 27183 + ... + 32588.

It is an arithmetic number, because the mean of its divisors is an integer number (14524596).

Almost surely, 2^161561013 is an apocalyptic number.

It is an amenable number.

161561013 is a deficient number, since it is larger than the sum of its proper divisors (70832523).

161561013 is a wasteful number, since it uses less digits than its factorization.

161561013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59844.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 161561013 is about 12710.6653248365. The cubic root of 161561013 is about 544.6433297433.

The spelling of 161561013 in words is "one hundred sixty-one million, five hundred sixty-one thousand, thirteen".