133731999 has 16 divisors (see below), whose sum is σ = 198847840. Its totient is φ = 88827840.

The previous prime is 133731943. The next prime is 133732003. The reversal of 133731999 is 999137331.

It is not a de Polignac number, because 133731999 - 2¹⁷ = 133600927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133731919) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1462 + ... + 16419.

It is an arithmetic number, because the mean of its divisors is an integer number (12427990).

Almost surely, 2^133731999 is an apocalyptic number.

133731999 is a deficient number, since it is larger than the sum of its proper divisors (65115841).

133731999 is a wasteful number, since it uses less digits than its factorization.

133731999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18167 (or 18161 counting only the distinct ones).

The product of its digits is 137781, while the sum is 45.

The square root of 133731999 is about 11564.2552289371. The cubic root of 133731999 is about 511.3816170680.

The spelling of 133731999 in words is "one hundred thirty-three million, seven hundred thirty-one thousand, nine hundred ninety-nine".