136421521 has 2 divisors, whose sum is σ = 136421522. Its totient is φ = 136421520.

The previous prime is 136421497. The next prime is 136421531. The reversal of 136421521 is 125124631.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104837121 + 31584400 = 10239^2 + 5620^2 .

It is a cyclic number.

It is not a de Polignac number, because 136421521 - 2⁵ = 136421489 is a prime.

It is a super-2 number, since 2×136421521² = 37221662783906882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (136421531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68210760 + 68210761.

It is an arithmetic number, because the mean of its divisors is an integer number (68210761).

Almost surely, 2^136421521 is an apocalyptic number.

It is an amenable number.

136421521 is a deficient number, since it is larger than the sum of its proper divisors (1).

136421521 is an equidigital number, since it uses as much as digits as its factorization.

136421521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 25.

The square root of 136421521 is about 11679.9623715147. The cubic root of 136421521 is about 514.7870687904.

The spelling of 136421521 in words is "one hundred thirty-six million, four hundred twenty-one thousand, five hundred twenty-one".