39634981 has 2 divisors, whose sum is σ = 39634982. Its totient is φ = 39634980.

The previous prime is 39634979. The next prime is 39635009. The reversal of 39634981 is 18943693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30580900 + 9054081 = 5530^2 + 3009^2 .

It is a cyclic number.

It is not a de Polignac number, because 39634981 - 2¹ = 39634979 is a prime.

It is a super-2 number, since 2×39634981² = 3141863437740722, which contains 22 as substring.

Together with 39634979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39634921) 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 as a sum of consecutive naturals, namely, 19817490 + 19817491.

It is an arithmetic number, because the mean of its divisors is an integer number (19817491).

Almost surely, 2^39634981 is an apocalyptic number.

It is an amenable number.

39634981 is a deficient number, since it is larger than the sum of its proper divisors (1).

39634981 is an equidigital number, since it uses as much as digits as its factorization.

39634981 is an odious number, because the sum of its binary digits is odd.

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

The square root of 39634981 is about 6295.6318983880. The cubic root of 39634981 is about 340.9517192991.

The spelling of 39634981 in words is "thirty-nine million, six hundred thirty-four thousand, nine hundred eighty-one".