39897842 has 4 divisors (see below), whose sum is σ = 59846766. Its totient is φ = 19948920.

The previous prime is 39897841. The next prime is 39897857. The reversal of 39897842 is 24879893.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24879893 = 3011 ⋅8263.

It can be written as a sum of positive squares in only one way, i.e., 21911761 + 17986081 = 4681^2 + 4241^2 .

It is not an unprimeable number, because it can be changed into a prime (39897841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9974459 + ... + 9974462.

Almost surely, 2^39897842 is an apocalyptic number.

39897842 is a deficient number, since it is larger than the sum of its proper divisors (19948924).

39897842 is a wasteful number, since it uses less digits than its factorization.

39897842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19948923.

The product of its digits is 870912, while the sum is 50.

The square root of 39897842 is about 6316.4738580952. The cubic root of 39897842 is about 341.7037949208.

The spelling of 39897842 in words is "thirty-nine million, eight hundred ninety-seven thousand, eight hundred forty-two".