136778771 has 4 divisors (see below), whose sum is σ = 138426792. Its totient is φ = 135130752.

The previous prime is 136778737. The next prime is 136778773. The reversal of 136778771 is 177877631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 177877631 = 3163 ⋅56237.

It is a cyclic number.

It is not a de Polignac number, because 136778771 - 2¹⁰ = 136777747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136778773) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 823886 + ... + 824051.

It is an arithmetic number, because the mean of its divisors is an integer number (34606698).

Almost surely, 2^136778771 is an apocalyptic number.

136778771 is a deficient number, since it is larger than the sum of its proper divisors (1648021).

136778771 is an equidigital number, since it uses as much as digits as its factorization.

136778771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648020.

The product of its digits is 345744, while the sum is 47.

The square root of 136778771 is about 11695.2456579586. The cubic root of 136778771 is about 515.2360384686.

The spelling of 136778771 in words is "one hundred thirty-six million, seven hundred seventy-eight thousand, seven hundred seventy-one".