136402561 has 4 divisors (see below), whose sum is σ = 136540372. Its totient is φ = 136264752.

The previous prime is 136402559. The next prime is 136402597. The reversal of 136402561 is 165204631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 111091600 + 25310961 = 10540^2 + 5031^2 .

It is a cyclic number.

It is not a de Polignac number, because 136402561 - 2¹ = 136402559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136402261) 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, 67410 + ... + 69403.

It is an arithmetic number, because the mean of its divisors is an integer number (34135093).

Almost surely, 2^136402561 is an apocalyptic number.

It is an amenable number.

136402561 is a deficient number, since it is larger than the sum of its proper divisors (137811).

136402561 is an equidigital number, since it uses as much as digits as its factorization.

136402561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137810.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 136402561 is about 11679.1506968615. The cubic root of 136402561 is about 514.7632191442.

The spelling of 136402561 in words is "one hundred thirty-six million, four hundred two thousand, five hundred sixty-one".