161751399 has 16 divisors (see below), whose sum is σ = 218557440. Its totient is φ = 106397600.

The previous prime is 161751377. The next prime is 161751409. The reversal of 161751399 is 993157161.

It is a cyclic number.

It is not a de Polignac number, because 161751399 - 2⁹ = 161750887 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 161751399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161751319) 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, 108034 + ... + 109520.

It is an arithmetic number, because the mean of its divisors is an integer number (13659840).

Almost surely, 2^161751399 is an apocalyptic number.

161751399 is a deficient number, since it is larger than the sum of its proper divisors (56806041).

161751399 is a wasteful number, since it uses less digits than its factorization.

161751399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1950.

The product of its digits is 51030, while the sum is 42.

The square root of 161751399 is about 12718.1523422233. The cubic root of 161751399 is about 544.8571844738.

The spelling of 161751399 in words is "one hundred sixty-one million, seven hundred fifty-one thousand, three hundred ninety-nine".