36439981 has 8 divisors (see below), whose sum is σ = 38122560. Its totient is φ = 34765632.

The previous prime is 36439961. The next prime is 36439987. The reversal of 36439981 is 18993463.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 36439981 - 2¹⁵ = 36407213 is a prime.

It is a super-2 number, since 2×36439981² = 2655744430560722, 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 (36439987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8130 + ... + 11788.

It is an arithmetic number, because the mean of its divisors is an integer number (4765320).

Almost surely, 2^36439981 is an apocalyptic number.

It is an amenable number.

36439981 is a deficient number, since it is larger than the sum of its proper divisors (1682579).

36439981 is a wasteful number, since it uses less digits than its factorization.

36439981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4115.

The product of its digits is 139968, while the sum is 43.

The square root of 36439981 is about 6036.5537353692. The cubic root of 36439981 is about 331.5324532365.

The spelling of 36439981 in words is "thirty-six million, four hundred thirty-nine thousand, nine hundred eighty-one".