199839640 has 384 divisors, whose sum is σ = 661893120. Its totient is φ = 53222400.

The previous prime is 199839623. The next prime is 199839659. The reversal of 199839640 is 46938991.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6446425 + ... + 6446455.

It is an arithmetic number, because the mean of its divisors is an integer number (1723680).

Almost surely, 2^199839640 is an apocalyptic number.

199839640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 199839640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330946560).

199839640 is an abundant number, since it is smaller than the sum of its proper divisors (462053480).

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

199839640 is a wasteful number, since it uses less digits than its factorization.

199839640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 199839640 is about 14136.4649046358. The cubic root of 199839640 is about 584.6472073557.

The spelling of 199839640 in words is "one hundred ninety-nine million, eight hundred thirty-nine thousand, six hundred forty".