199909142640 has 160 divisors (see below), whose sum is σ = 689753352960. Its totient is φ = 53217950976.

The previous prime is 199909142591. The next prime is 199909142659. The reversal of 199909142640 is 46241909991.

199909142640 is a `hidden beast` number, since 1 + 9 + 9 + 90 + 91 + 426 + 40 = 666.

It is a super-2 number, since 2×199909142640² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1189087 + ... + 1346753.

It is an arithmetic number, because the mean of its divisors is an integer number (4310958456).

Almost surely, 2^199909142640 is an apocalyptic number.

199909142640 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 199909142640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344876676480).

199909142640 is an abundant number, since it is smaller than the sum of its proper divisors (489844210320).

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

199909142640 is a wasteful number, since it uses less digits than its factorization.

199909142640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158276 (or 158264 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The spelling of 199909142640 in words is "one hundred ninety-nine billion, nine hundred nine million, one hundred forty-two thousand, six hundred forty".