4891021 has 4 divisors (see below), whose sum is σ = 4922332. Its totient is φ = 4859712.

The previous prime is 4891001. The next prime is 4891027. The reversal of 4891021 is 1201984.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1334025 + 3556996 = 1155^2 + 1886^2 .

It is a cyclic number.

It is not a de Polignac number, because 4891021 - 2¹¹ = 4888973 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 (4891027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15420 + ... + 15733.

It is an arithmetic number, because the mean of its divisors is an integer number (1230583).

Almost surely, 2^4891021 is an apocalyptic number.

It is an amenable number.

4891021 is a deficient number, since it is larger than the sum of its proper divisors (31311).

4891021 is a wasteful number, since it uses less digits than its factorization.

4891021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31310.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 4891021 is about 2211.5652827805. The cubic root of 4891021 is about 169.7461146818.

The spelling of 4891021 in words is "four million, eight hundred ninety-one thousand, twenty-one".