3778421 has 2 divisors, whose sum is σ = 3778422. Its totient is φ = 3778420.

The previous prime is 3778399. The next prime is 3778427. The reversal of 3778421 is 1248773.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3648100 + 130321 = 1910^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 3778421 - 2¹⁸ = 3516277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3778427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1889210 + 1889211.

It is an arithmetic number, because the mean of its divisors is an integer number (1889211).

Almost surely, 2^3778421 is an apocalyptic number.

It is an amenable number.

3778421 is a deficient number, since it is larger than the sum of its proper divisors (1).

3778421 is an equidigital number, since it uses as much as digits as its factorization.

3778421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 32.

The square root of 3778421 is about 1943.8160921239. The cubic root of 3778421 is about 155.7531296955.

The spelling of 3778421 in words is "three million, seven hundred seventy-eight thousand, four hundred twenty-one".