161651730 has 16 divisors (see below), whose sum is σ = 387964224. Its totient is φ = 43107120.

The previous prime is 161651729. The next prime is 161651741. The reversal of 161651730 is 37156161.

It is a super-2 number, since 2×161651730² = 52262563623985800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 5388391 = 161651730 / (1 + 6 + 1 + 6 + 5 + 1 + 7 + 3 + 0).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2694166 + ... + 2694225.

It is an arithmetic number, because the mean of its divisors is an integer number (24247764).

Almost surely, 2^161651730 is an apocalyptic number.

161651730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161651730 is an abundant number, since it is smaller than the sum of its proper divisors (226312494).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161651730 is a wasteful number, since it uses less digits than its factorization.

161651730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5388401.

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 161651730 is about 12714.2333626531. The cubic root of 161651730 is about 544.7452502980.

The spelling of 161651730 in words is "one hundred sixty-one million, six hundred fifty-one thousand, seven hundred thirty".