36780721 has 4 divisors (see below), whose sum is σ = 36794212. Its totient is φ = 36767232.

The previous prime is 36780691. The next prime is 36780727. The reversal of 36780721 is 12708763.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12708763 = 127 ⋅100069.

It can be written as a sum of positive squares in 2 ways, for example, as 5588496 + 31192225 = 2364^2 + 5585^2 .

It is a cyclic number.

It is not a de Polignac number, because 36780721 - 2⁷ = 36780593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (36780727) 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, 1056 + ... + 8641.

It is an arithmetic number, because the mean of its divisors is an integer number (9198553).

Almost surely, 2^36780721 is an apocalyptic number.

It is an amenable number.

36780721 is a deficient number, since it is larger than the sum of its proper divisors (13491).

36780721 is an equidigital number, since it uses as much as digits as its factorization.

36780721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13490.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 36780721 is about 6064.7111225515. The cubic root of 36780721 is about 332.5626045270.

The spelling of 36780721 in words is "thirty-six million, seven hundred eighty thousand, seven hundred twenty-one".