136978493 has 2 divisors, whose sum is σ = 136978494. Its totient is φ = 136978492.

The previous prime is 136978483. The next prime is 136978507. The reversal of 136978493 is 394879631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72369049 + 64609444 = 8507^2 + 8038^2 .

It is a cyclic number.

It is not a de Polignac number, because 136978493 - 2²² = 132784189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136978423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68489246 + 68489247.

It is an arithmetic number, because the mean of its divisors is an integer number (68489247).

Almost surely, 2^136978493 is an apocalyptic number.

It is an amenable number.

136978493 is a deficient number, since it is larger than the sum of its proper divisors (1).

136978493 is an equidigital number, since it uses as much as digits as its factorization.

136978493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 50.

The square root of 136978493 is about 11703.7811411526. The cubic root of 136978493 is about 515.4866960955.

The spelling of 136978493 in words is "one hundred thirty-six million, nine hundred seventy-eight thousand, four hundred ninety-three".