3987421 has 2 divisors, whose sum is σ = 3987422. Its totient is φ = 3987420.

The previous prime is 3987409. The next prime is 3987427. The reversal of 3987421 is 1247893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3980025 + 7396 = 1995^2 + 86^2 .

It is an emirp because it is prime and its reverse (1247893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3987421 - 2¹³ = 3979229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3987427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1993710 + 1993711.

It is an arithmetic number, because the mean of its divisors is an integer number (1993711).

Almost surely, 2^3987421 is an apocalyptic number.

It is an amenable number.

3987421 is a deficient number, since it is larger than the sum of its proper divisors (1).

3987421 is an equidigital number, since it uses as much as digits as its factorization.

3987421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 34.

The square root of 3987421 is about 1996.8527737417. The cubic root of 3987421 is about 158.5735311481.

The spelling of 3987421 in words is "three million, nine hundred eighty-seven thousand, four hundred twenty-one".