1189399820 has 48 divisors (see below), whose sum is σ = 2873515008. Its totient is φ = 405086400.

The previous prime is 1189399807. The next prime is 1189399837. The reversal of 1189399820 is 289939811.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6992 + ... + 49271.

It is an arithmetic number, because the mean of its divisors is an integer number (59864896).

Almost surely, 2^1189399820 is an apocalyptic number.

1189399820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1189399820 is an abundant number, since it is smaller than the sum of its proper divisors (1684115188).

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

1189399820 is a wasteful number, since it uses less digits than its factorization.

1189399820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56430 (or 56428 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 1189399820 is about 34487.6763496760. The cubic root of 1189399820 is about 1059.5203181468.

The spelling of 1189399820 in words is "one billion, one hundred eighty-nine million, three hundred ninety-nine thousand, eight hundred twenty".