39899961 has 12 divisors (see below), whose sum is σ = 58144788. Its totient is φ = 26363904.

The previous prime is 39899957. The next prime is 39899999. The reversal of 39899961 is 16999893.

It can be written as a sum of positive squares in 2 ways, for example, as 962361 + 38937600 = 981^2 + 6240^2 .

It is not a de Polignac number, because 39899961 - 2² = 39899957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 39899898 and 39899907.

It is not an unprimeable number, because it can be changed into a prime (39899161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18600 + ... + 20633.

It is an arithmetic number, because the mean of its divisors is an integer number (4845399).

Almost surely, 2^39899961 is an apocalyptic number.

It is an amenable number.

39899961 is a deficient number, since it is larger than the sum of its proper divisors (18244827).

39899961 is a wasteful number, since it uses less digits than its factorization.

39899961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39352 (or 39349 counting only the distinct ones).

The product of its digits is 944784, while the sum is 54.

The square root of 39899961 is about 6316.6415918588. The cubic root of 39899961 is about 341.7098441831.

The spelling of 39899961 in words is "thirty-nine million, eight hundred ninety-nine thousand, nine hundred sixty-one".