4901821 has 4 divisors (see below), whose sum is σ = 4907644. Its totient is φ = 4896000.

The previous prime is 4901807. The next prime is 4901849. The reversal of 4901821 is 1281094.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2842596 + 2059225 = 1686^2 + 1435^2 .

It is a cyclic number.

It is not a de Polignac number, because 4901821 - 2⁷ = 4901693 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 (4901801) 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, 1380 + ... + 3421.

It is an arithmetic number, because the mean of its divisors is an integer number (1226911).

Almost surely, 2^4901821 is an apocalyptic number.

It is an amenable number.

4901821 is a deficient number, since it is larger than the sum of its proper divisors (5823).

4901821 is a wasteful number, since it uses less digits than its factorization.

4901821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5822.

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

The square root of 4901821 is about 2214.0056458826. The cubic root of 4901821 is about 169.8709632110.

Subtracting from 4901821 its sum of digits (25), we obtain a square (4901796 = 2214²).

The spelling of 4901821 in words is "four million, nine hundred one thousand, eight hundred twenty-one".