3890021 has 2 divisors, whose sum is σ = 3890022. Its totient is φ = 3890020.
The previous prime is 3890011. The next prime is 3890027. The reversal of 3890021 is 1200983.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1999396 + 1890625 = 1414^2 + 1375^2 .
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-3890021 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is an Ulam number.
It is a Curzon number.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (3890027) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1945010 + 1945011.
It is an arithmetic number, because the mean of its divisors is an integer number (1945011).
Almost surely, 23890021 is an apocalyptic number.
It is an amenable number.
3890021 is a deficient number, since it is larger than the sum of its proper divisors (1).
3890021 is an equidigital number, since it uses as much as digits as its factorization.
3890021 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 432, while the sum is 23.
The square root of 3890021 is about 1972.3136160357. The cubic root of 3890021 is about 157.2717243979.
The spelling of 3890021 in words is "three million, eight hundred ninety thousand, twenty-one".
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