136421561 has 4 divisors (see below), whose sum is σ = 136716672. Its totient is φ = 136126452.

The previous prime is 136421531. The next prime is 136421563. The reversal of 136421561 is 165124631.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 136421561 - 2⁶ = 136421497 is a prime.

It is a super-2 number, since 2×136421561² = 37221684611353442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136421563) 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, 146861 + ... + 147786.

It is an arithmetic number, because the mean of its divisors is an integer number (34179168).

Almost surely, 2^136421561 is an apocalyptic number.

It is an amenable number.

136421561 is a deficient number, since it is larger than the sum of its proper divisors (295111).

136421561 is an equidigital number, since it uses as much as digits as its factorization.

136421561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295110.

The product of its digits is 4320, while the sum is 29.

The square root of 136421561 is about 11679.9640838489. The cubic root of 136421561 is about 514.7871191038.

The spelling of 136421561 in words is "one hundred thirty-six million, four hundred twenty-one thousand, five hundred sixty-one".