161537639 has 8 divisors (see below), whose sum is σ = 170625840. Its totient is φ = 152508096.

The previous prime is 161537611. The next prime is 161537641. The reversal of 161537639 is 936735161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161537639 - 2¹² = 161533543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161537596 and 161537605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161537039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8942 + ... + 20075.

It is an arithmetic number, because the mean of its divisors is an integer number (21328230).

Almost surely, 2^161537639 is an apocalyptic number.

161537639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

161537639 is a deficient number, since it is larger than the sum of its proper divisors (9088201).

161537639 is a wasteful number, since it uses less digits than its factorization.

161537639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29329.

The product of its digits is 102060, while the sum is 41.

The square root of 161537639 is about 12709.7458275136. The cubic root of 161537639 is about 544.6170628717.

The spelling of 161537639 in words is "one hundred sixty-one million, five hundred thirty-seven thousand, six hundred thirty-nine".