36721781 has 4 divisors (see below), whose sum is σ = 36947232. Its totient is φ = 36496332.

The previous prime is 36721771. The next prime is 36721787. The reversal of 36721781 is 18712763.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-36721781 is a prime.

It is a super-2 number, since 2×36721781² = 2696978399623922, 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 (36721787) 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 3 ways as a sum of consecutive naturals, for example, 112481 + ... + 112806.

It is an arithmetic number, because the mean of its divisors is an integer number (9236808).

Almost surely, 2^36721781 is an apocalyptic number.

It is an amenable number.

36721781 is a deficient number, since it is larger than the sum of its proper divisors (225451).

36721781 is a wasteful number, since it uses less digits than its factorization.

36721781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225450.

The product of its digits is 14112, while the sum is 35.

The square root of 36721781 is about 6059.8499156332. The cubic root of 36721781 is about 332.3848690283.

The spelling of 36721781 in words is "thirty-six million, seven hundred twenty-one thousand, seven hundred eighty-one".