39545981 has 2 divisors, whose sum is σ = 39545982. Its totient is φ = 39545980.

The previous prime is 39545971. The next prime is 39545983. The reversal of 39545981 is 18954593.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38316100 + 1229881 = 6190^2 + 1109^2 .

It is a cyclic number.

It is not a de Polignac number, because 39545981 - 2¹⁰ = 39544957 is a prime.

It is a super-2 number, since 2×39545981² = 3127769226504722, which contains 22 as substring.

Together with 39545983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39545983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19772990 + 19772991.

It is an arithmetic number, because the mean of its divisors is an integer number (19772991).

Almost surely, 2^39545981 is an apocalyptic number.

It is an amenable number.

39545981 is a deficient number, since it is larger than the sum of its proper divisors (1).

39545981 is an equidigital number, since it uses as much as digits as its factorization.

39545981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 44.

The square root of 39545981 is about 6288.5595329932. The cubic root of 39545981 is about 340.6963266843.

The spelling of 39545981 in words is "thirty-nine million, five hundred forty-five thousand, nine hundred eighty-one".