36161721 has 10 divisors (see below), whose sum is σ = 54019482. Its totient is φ = 24107760.

The previous prime is 36161687. The next prime is 36161777. The reversal of 36161721 is 12716163.

36161721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 28676025 + 7485696 = 5355^2 + 2736^2 .

It is not a de Polignac number, because 36161721 - 2¹⁰ = 36160697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (36166721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 223140 + ... + 223301.

Almost surely, 2^36161721 is an apocalyptic number.

It is an amenable number.

36161721 is a deficient number, since it is larger than the sum of its proper divisors (17857761).

36161721 is an equidigital number, since it uses as much as digits as its factorization.

36161721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446453 (or 446444 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 36161721 is about 6013.4616486679. The cubic root of 36161721 is about 330.6864224443.

Adding to 36161721 its reverse (12716163), we get a palindrome (48877884).

It can be divided in two parts, 361617 and 21, that multiplied together give a palindrome (7593957).

The spelling of 36161721 in words is "thirty-six million, one hundred sixty-one thousand, seven hundred twenty-one".