4781365621 has 2 divisors, whose sum is σ = 4781365622. Its totient is φ = 4781365620.

The previous prime is 4781365619. The next prime is 4781365639. The reversal of 4781365621 is 1265631874.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4745832100 + 35533521 = 68890^2 + 5961^2 .

It is a cyclic number.

It is not a de Polignac number, because 4781365621 - 2¹ = 4781365619 is a prime.

It is a super-2 number, since 2×4781365621² = 45722914403361431282, which contains 22 as substring.

Together with 4781365619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4781305621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2390682810 + 2390682811.

It is an arithmetic number, because the mean of its divisors is an integer number (2390682811).

Almost surely, 2^4781365621 is an apocalyptic number.

It is an amenable number.

4781365621 is a deficient number, since it is larger than the sum of its proper divisors (1).

4781365621 is an equidigital number, since it uses as much as digits as its factorization.

4781365621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 43.

The square root of 4781365621 is about 69147.4194818577. The cubic root of 4781365621 is about 1684.6796047186.

The spelling of 4781365621 in words is "four billion, seven hundred eighty-one million, three hundred sixty-five thousand, six hundred twenty-one".