189878257 has 8 divisors (see below), whose sum is σ = 195535872. Its totient is φ = 184269600.

The previous prime is 189878243. The next prime is 189878303. The reversal of 189878257 is 752878981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 189878257 - 2¹⁵ = 189845489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 189878198 and 189878207.

It is not an unprimeable number, because it can be changed into a prime (189872257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4293 + ... + 19954.

It is an arithmetic number, because the mean of its divisors is an integer number (24441984).

Almost surely, 2^189878257 is an apocalyptic number.

It is an amenable number.

189878257 is a deficient number, since it is larger than the sum of its proper divisors (5657615).

189878257 is a wasteful number, since it uses less digits than its factorization.

189878257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24479.

The product of its digits is 2257920, while the sum is 55.

The square root of 189878257 is about 13779.6319617035. The cubic root of 189878257 is about 574.7668942953.

The spelling of 189878257 in words is "one hundred eighty-nine million, eight hundred seventy-eight thousand, two hundred fifty-seven".