161261099 has 4 divisors (see below), whose sum is σ = 170747064. Its totient is φ = 151775136.

The previous prime is 161261069. The next prime is 161261129. The reversal of 161261099 is 990162161.

161261099 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (161261069) and next prime (161261129).

It is a cyclic number.

It is not a de Polignac number, because 161261099 - 2²⁰ = 160212523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161261029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4742957 + ... + 4742990.

It is an arithmetic number, because the mean of its divisors is an integer number (42686766).

Almost surely, 2^161261099 is an apocalyptic number.

161261099 is a deficient number, since it is larger than the sum of its proper divisors (9485965).

161261099 is an equidigital number, since it uses as much as digits as its factorization.

161261099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9485964.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 161261099 is about 12698.8621143786. The cubic root of 161261099 is about 544.3061045327.

The spelling of 161261099 in words is "one hundred sixty-one million, two hundred sixty-one thousand, ninety-nine".