5661525421 has 2 divisors, whose sum is σ = 5661525422. Its totient is φ = 5661525420.

The previous prime is 5661525409. The next prime is 5661525427. The reversal of 5661525421 is 1245251665.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2853055396 + 2808470025 = 53414^2 + 52995^2 .

It is a cyclic number.

It is not a de Polignac number, because 5661525421 - 2¹⁹ = 5661001133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5661525427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2830762710 + 2830762711.

It is an arithmetic number, because the mean of its divisors is an integer number (2830762711).

Almost surely, 2^5661525421 is an apocalyptic number.

It is an amenable number.

5661525421 is a deficient number, since it is larger than the sum of its proper divisors (1).

5661525421 is an equidigital number, since it uses as much as digits as its factorization.

5661525421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72000, while the sum is 37.

The square root of 5661525421 is about 75243.1087940949. The cubic root of 5661525421 is about 1782.2877436235.

The spelling of 5661525421 in words is "five billion, six hundred sixty-one million, five hundred twenty-five thousand, four hundred twenty-one".