39961669 has 4 divisors (see below), whose sum is σ = 43594560. Its totient is φ = 36328780.

The previous prime is 39961661. The next prime is 39961673. The reversal of 39961669 is 96616993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 39961669 - 2³ = 39961661 is a prime.

It is a super-2 number, since 2×39961669² = 3193869978531122, 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 (39961661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1816429 + ... + 1816450.

It is an arithmetic number, because the mean of its divisors is an integer number (10898640).

Almost surely, 2^39961669 is an apocalyptic number.

It is an amenable number.

39961669 is a deficient number, since it is larger than the sum of its proper divisors (3632891).

39961669 is a wasteful number, since it uses less digits than its factorization.

39961669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3632890.

The product of its digits is 472392, while the sum is 49.

The square root of 39961669 is about 6321.5242623912. The cubic root of 39961669 is about 341.8859126088.

It can be divided in two parts, 3996 and 1669, that added together give a palindrome (5665).

The spelling of 39961669 in words is "thirty-nine million, nine hundred sixty-one thousand, six hundred sixty-nine".