161980380 has 36 divisors (see below), whose sum is σ = 491341032. Its totient is φ = 43194720.

The previous prime is 161980373. The next prime is 161980387. The reversal of 161980380 is 83089161.

161980380 is a `hidden beast` number, since 1 + 619 + 8 + 0 + 38 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (161980373) and next prime (161980387).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161980387) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 449766 + ... + 450125.

It is an arithmetic number, because the mean of its divisors is an integer number (13648362).

Almost surely, 2^161980380 is an apocalyptic number.

161980380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161980380 is an abundant number, since it is smaller than the sum of its proper divisors (329360652).

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

161980380 is a wasteful number, since it uses less digits than its factorization.

161980380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899906 (or 899901 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 161980380 is about 12727.1512916285. The cubic root of 161980380 is about 545.1141696117.

The spelling of 161980380 in words is "one hundred sixty-one million, nine hundred eighty thousand, three hundred eighty".