3778021 has 4 divisors (see below), whose sum is σ = 4068652. Its totient is φ = 3487392.

The previous prime is 3778007. The next prime is 3778039. The reversal of 3778021 is 1208773.

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: 1208773 = 43 ⋅28111.

It can be written as a sum of positive squares in 2 ways, for example, as 1185921 + 2592100 = 1089^2 + 1610^2 .

It is a cyclic number.

It is not a de Polignac number, because 3778021 - 2⁵ = 3777989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3778051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145296 + ... + 145321.

It is an arithmetic number, because the mean of its divisors is an integer number (1017163).

Almost surely, 2^3778021 is an apocalyptic number.

It is an amenable number.

3778021 is a deficient number, since it is larger than the sum of its proper divisors (290631).

3778021 is a wasteful number, since it uses less digits than its factorization.

3778021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290630.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 3778021 is about 1943.7131990085. The cubic root of 3778021 is about 155.7476332681.

The spelling of 3778021 in words is "three million, seven hundred seventy-eight thousand, twenty-one".