2563642421 has 4 divisors (see below), whose sum is σ = 2632930092. Its totient is φ = 2494354752.

The previous prime is 2563642387. The next prime is 2563642493. The reversal of 2563642421 is 1242463652.

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 1332615025 + 1231027396 = 36505^2 + 35086^2 .

It is a cyclic number.

It is not a de Polignac number, because 2563642421 - 2⁶ = 2563642357 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 (2563642121) 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, 34643780 + ... + 34643853.

It is an arithmetic number, because the mean of its divisors is an integer number (658232523).

Almost surely, 2^2563642421 is an apocalyptic number.

It is an amenable number.

2563642421 is a deficient number, since it is larger than the sum of its proper divisors (69287671).

2563642421 is an equidigital number, since it uses as much as digits as its factorization.

2563642421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69287670.

The product of its digits is 69120, while the sum is 35.

The square root of 2563642421 is about 50632.4246012375. The cubic root of 2563642421 is about 1368.6292469914.

The spelling of 2563642421 in words is "two billion, five hundred sixty-three million, six hundred forty-two thousand, four hundred twenty-one".