133773981 has 24 divisors (see below), whose sum is σ = 200444832. Its totient is φ = 78645600.

The previous prime is 133773979. The next prime is 133774007. The reversal of 133773981 is 189377331.

It is not a de Polignac number, because 133773981 - 2¹ = 133773979 is a prime.

It is a super-2 number, since 2×133773981² = 35790955985176722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133773931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 403986 + ... + 404316.

It is an arithmetic number, because the mean of its divisors is an integer number (8351868).

Almost surely, 2^133773981 is an apocalyptic number.

133773981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133773981 is a deficient number, since it is larger than the sum of its proper divisors (66670851).

133773981 is an equidigital number, since it uses as much as digits as its factorization.

133773981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713 (or 382 counting only the distinct ones).

The product of its digits is 95256, while the sum is 42.

The square root of 133773981 is about 11566.0702487924. The cubic root of 133773981 is about 511.4351235263.

The spelling of 133773981 in words is "one hundred thirty-three million, seven hundred seventy-three thousand, nine hundred eighty-one".