189720389 has 2 divisors, whose sum is σ = 189720390. Its totient is φ = 189720388.

The previous prime is 189720383. The next prime is 189720413. The reversal of 189720389 is 983027981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99660289 + 90060100 = 9983^2 + 9490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189720389 is a prime.

It is a super-2 number, since 2×189720389² = 71987652004622642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189720383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94860194 + 94860195.

It is an arithmetic number, because the mean of its divisors is an integer number (94860195).

Almost surely, 2^189720389 is an apocalyptic number.

It is an amenable number.

189720389 is a deficient number, since it is larger than the sum of its proper divisors (1).

189720389 is an equidigital number, since it uses as much as digits as its factorization.

189720389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 47.

The square root of 189720389 is about 13773.9024608133. The cubic root of 189720389 is about 574.6075598179.

The spelling of 189720389 in words is "one hundred eighty-nine million, seven hundred twenty thousand, three hundred eighty-nine".