133998381 has 40 divisors (see below), whose sum is σ = 222156000. Its totient is φ = 79803360.

The previous prime is 133998377. The next prime is 133998383. The reversal of 133998381 is 183899331.

It is a happy number.

It is not a de Polignac number, because 133998381 - 2² = 133998377 is a prime.

It is a super-2 number, since 2×133998381² = 35911132221242322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133998383) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 51295 + ... + 53843.

It is an arithmetic number, because the mean of its divisors is an integer number (5553900).

Almost surely, 2^133998381 is an apocalyptic number.

133998381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133998381 is a deficient number, since it is larger than the sum of its proper divisors (88157619).

133998381 is a wasteful number, since it uses less digits than its factorization.

133998381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2631 (or 2622 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 133998381 is about 11575.7669724299. The cubic root of 133998381 is about 511.7209337886.

The spelling of 133998381 in words is "one hundred thirty-three million, nine hundred ninety-eight thousand, three hundred eighty-one".