134991781 has 16 divisors (see below), whose sum is σ = 149688000. Its totient is φ = 121155328.

The previous prime is 134991757. The next prime is 134991793. The reversal of 134991781 is 187199431.

134991781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 134991781 - 2⁷ = 134991653 is a prime.

It is a super-2 number, since 2×134991781² = 36445561875103922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (134991481) 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, 39270 + ... + 42568.

It is an arithmetic number, because the mean of its divisors is an integer number (9355500).

Almost surely, 2^134991781 is an apocalyptic number.

It is an amenable number.

134991781 is a deficient number, since it is larger than the sum of its proper divisors (14696219).

134991781 is a wasteful number, since it uses less digits than its factorization.

134991781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3428.

The product of its digits is 54432, while the sum is 43.

The square root of 134991781 is about 11618.5963437930. The cubic root of 134991781 is about 512.9823732048.

The spelling of 134991781 in words is "one hundred thirty-four million, nine hundred ninety-one thousand, seven hundred eighty-one".