161540387 has 4 divisors (see below), whose sum is σ = 161574120. Its totient is φ = 161506656.

The previous prime is 161540381. The next prime is 161540389. The reversal of 161540387 is 783045161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 783045161 = 53 ⋅14774437.

It is a cyclic number.

It is not a de Polignac number, because 161540387 - 2⁴ = 161540371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161540381) 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, 8198 + ... + 19755.

It is an arithmetic number, because the mean of its divisors is an integer number (40393530).

Almost surely, 2^161540387 is an apocalyptic number.

161540387 is a deficient number, since it is larger than the sum of its proper divisors (33733).

161540387 is an equidigital number, since it uses as much as digits as its factorization.

161540387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33732.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 161540387 is about 12709.8539330710. The cubic root of 161540387 is about 544.6201511080.

The spelling of 161540387 in words is "one hundred sixty-one million, five hundred forty thousand, three hundred eighty-seven".