39901261009 has 3 divisors (see below), whose sum is σ = 39901460763. Its totient is φ = 39901061256.

The previous prime is 39901260989. The next prime is 39901261021. The reversal of 39901261009 is 90016210993.

The square root of 39901261009 is 199753.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 27193659025 + 12707601984 = 164905^2 + 112728^2 .

It is not a de Polignac number, because 39901261009 - 2⁵ = 39901260977 is a prime.

It is a super-2 number, since 2×39901261009² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39901261909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 99877 + ... + 299629.

It is an arithmetic number, because the mean of its divisors is an integer number (13300486921).

Almost surely, 2^39901261009 is an apocalyptic number.

39901261009 is the 199753-rd square number.

39901261009 is the 99877-th centered octagonal number.

It is an amenable number.

39901261009 is a deficient number, since it is larger than the sum of its proper divisors (199754).

39901261009 is an frugal number, since it uses more digits than its factorization.

39901261009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399506 (or 199753 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 40.

The spelling of 39901261009 in words is "thirty-nine billion, nine hundred one million, two hundred sixty-one thousand, nine".