136619721 has 12 divisors (see below), whose sum is σ = 225531072. Its totient is φ = 78068376.

The previous prime is 136619699. The next prime is 136619737. The reversal of 136619721 is 127916631.

136619721 is a `hidden beast` number, since 1 + 36 + 619 + 7 + 2 + 1 = 666.

It is not a de Polignac number, because 136619721 - 2⁵ = 136619689 is a prime.

It is a super-2 number, since 2×136619721² = 37329896332235682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (136619521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1084221 + ... + 1084346.

It is an arithmetic number, because the mean of its divisors is an integer number (18794256).

Almost surely, 2^136619721 is an apocalyptic number.

It is an amenable number.

136619721 is a deficient number, since it is larger than the sum of its proper divisors (88911351).

136619721 is a wasteful number, since it uses less digits than its factorization.

136619721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168580 (or 2168577 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 136619721 is about 11688.4439084080. The cubic root of 136619721 is about 515.0362509437.

The spelling of 136619721 in words is "one hundred thirty-six million, six hundred nineteen thousand, seven hundred twenty-one".