133456781 has 2 divisors, whose sum is σ = 133456782. Its totient is φ = 133456780.

The previous prime is 133456747. The next prime is 133456823. The reversal of 133456781 is 187654331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 100681156 + 32775625 = 10034^2 + 5725^2 .

It is a cyclic number.

It is not a de Polignac number, because 133456781 - 2⁶ = 133456717 is a prime.

It is a super-2 number, since 2×133456781² = 35621424789763922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133456721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66728390 + 66728391.

It is an arithmetic number, because the mean of its divisors is an integer number (66728391).

Almost surely, 2^133456781 is an apocalyptic number.

It is an amenable number.

133456781 is a deficient number, since it is larger than the sum of its proper divisors (1).

133456781 is an equidigital number, since it uses as much as digits as its factorization.

133456781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 38.

The square root of 133456781 is about 11552.3495878544. The cubic root of 133456781 is about 511.0305714812.

The spelling of 133456781 in words is "one hundred thirty-three million, four hundred fifty-six thousand, seven hundred eighty-one".