189870409 has 2 divisors, whose sum is σ = 189870410. Its totient is φ = 189870408.

The previous prime is 189870403. The next prime is 189870427. The reversal of 189870409 is 904078981.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107060409 + 82810000 = 10347^2 + 9100^2 .

It is a cyclic number.

It is not a de Polignac number, because 189870409 - 2¹¹ = 189868361 is a prime.

It is not a weakly prime, because it can be changed into another prime (189870403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94935204 + 94935205.

It is an arithmetic number, because the mean of its divisors is an integer number (94935205).

Almost surely, 2^189870409 is an apocalyptic number.

It is an amenable number.

189870409 is a deficient number, since it is larger than the sum of its proper divisors (1).

189870409 is an equidigital number, since it uses as much as digits as its factorization.

189870409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 189870409 is about 13779.3471906328. The cubic root of 189870409 is about 574.7589754797.

The spelling of 189870409 in words is "one hundred eighty-nine million, eight hundred seventy thousand, four hundred nine".