189978520 has 16 divisors (see below), whose sum is σ = 427451760. Its totient is φ = 75991392.

The previous prime is 189978517. The next prime is 189978521. The reversal of 189978520 is 25879981.

It is a super-2 number, since 2×189978520² = 72183676122780800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189978521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2374692 + ... + 2374771.

It is an arithmetic number, because the mean of its divisors is an integer number (26715735).

Almost surely, 2^189978520 is an apocalyptic number.

189978520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

189978520 is an abundant number, since it is smaller than the sum of its proper divisors (237473240).

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

189978520 is a wasteful number, since it uses less digits than its factorization.

189978520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4749474 (or 4749470 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 49.

The square root of 189978520 is about 13783.2695685748. The cubic root of 189978520 is about 574.8680428132.

The spelling of 189978520 in words is "one hundred eighty-nine million, nine hundred seventy-eight thousand, five hundred twenty".