189720450 has 72 divisors (see below), whose sum is σ = 512872308. Its totient is φ = 50279040.

The previous prime is 189720437. The next prime is 189720451. The reversal of 189720450 is 54027981.

189720450 is a `hidden beast` number, since 189 + 7 + 20 + 450 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 158684409 + 31036041 = 12597^2 + 5571^2 .

It is not an unprimeable number, because it can be changed into a prime (189720451) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 76632 + ... + 79068.

Almost surely, 2^189720450 is an apocalyptic number.

189720450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 189720450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256436154).

189720450 is an abundant number, since it is smaller than the sum of its proper divisors (323151858).

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

189720450 is a wasteful number, since it uses less digits than its factorization.

189720450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628 (or 2620 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 189720450 is about 13773.9046751457. The cubic root of 189720450 is about 574.6076214016.

The spelling of 189720450 in words is "one hundred eighty-nine million, seven hundred twenty thousand, four hundred fifty".