161649420 has 24 divisors (see below), whose sum is σ = 452618544. Its totient is φ = 43106496.

The previous prime is 161649419. The next prime is 161649437. The reversal of 161649420 is 24946161.

It is a super-2 number, since 2×161649420² = 52261069972672800, which contains 22 as substring.

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, 1347019 + ... + 1347138.

It is an arithmetic number, because the mean of its divisors is an integer number (18859106).

Almost surely, 2^161649420 is an apocalyptic number.

161649420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161649420 is an abundant number, since it is smaller than the sum of its proper divisors (290969124).

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

161649420 is a wasteful number, since it uses less digits than its factorization.

161649420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2694169 (or 2694167 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 161649420 is about 12714.1425192578. The cubic root of 161649420 is about 544.7426554860.

The spelling of 161649420 in words is "one hundred sixty-one million, six hundred forty-nine thousand, four hundred twenty".