39868421 has 2 divisors, whose sum is σ = 39868422. Its totient is φ = 39868420.

The previous prime is 39868399. The next prime is 39868427. The reversal of 39868421 is 12486893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20376196 + 19492225 = 4514^2 + 4415^2 .

It is a cyclic number.

It is not a de Polignac number, because 39868421 - 2⁶ = 39868357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39868427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19934210 + 19934211.

It is an arithmetic number, because the mean of its divisors is an integer number (19934211).

Almost surely, 2^39868421 is an apocalyptic number.

It is an amenable number.

39868421 is a deficient number, since it is larger than the sum of its proper divisors (1).

39868421 is an equidigital number, since it uses as much as digits as its factorization.

39868421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 41.

The square root of 39868421 is about 6314.1445184601. The cubic root of 39868421 is about 341.6197825284.

The spelling of 39868421 in words is "thirty-nine million, eight hundred sixty-eight thousand, four hundred twenty-one".