36805781 has 4 divisors (see below), whose sum is σ = 36931692. Its totient is φ = 36679872.

The previous prime is 36805771. The next prime is 36805817. The reversal of 36805781 is 18750863.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18879025 + 17926756 = 4345^2 + 4234^2 .

It is a cyclic number.

It is not a de Polignac number, because 36805781 - 2²² = 32611477 is a prime.

It is a super-2 number, since 2×36805781² = 2709331030039922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36805751) 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, 62516 + ... + 63101.

It is an arithmetic number, because the mean of its divisors is an integer number (9232923).

Almost surely, 2^36805781 is an apocalyptic number.

It is an amenable number.

36805781 is a deficient number, since it is larger than the sum of its proper divisors (125911).

36805781 is a wasteful number, since it uses less digits than its factorization.

36805781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125910.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 36805781 is about 6066.7768213443. The cubic root of 36805781 is about 332.6381162499.

The spelling of 36805781 in words is "thirty-six million, eight hundred five thousand, seven hundred eighty-one".