36861781 has 4 divisors (see below), whose sum is σ = 40212864. Its totient is φ = 33510700.

The previous prime is 36861757. The next prime is 36861787. The reversal of 36861781 is 18716863.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18716863 = 11 ⋅1701533.

It is a cyclic number.

It is not a de Polignac number, because 36861781 - 2⁵ = 36861749 is a prime.

It is a super-2 number, since 2×36861781² = 2717581796983922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36861787) 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, 1675525 + ... + 1675546.

It is an arithmetic number, because the mean of its divisors is an integer number (10053216).

Almost surely, 2^36861781 is an apocalyptic number.

It is an amenable number.

36861781 is a deficient number, since it is larger than the sum of its proper divisors (3351083).

36861781 is a wasteful number, since it uses less digits than its factorization.

36861781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351082.

The product of its digits is 48384, while the sum is 40.

The square root of 36861781 is about 6071.3903679470. The cubic root of 36861781 is about 332.8067337389.

The spelling of 36861781 in words is "thirty-six million, eight hundred sixty-one thousand, seven hundred eighty-one".