7972542421 has 2 divisors, whose sum is σ = 7972542422. Its totient is φ = 7972542420.

The previous prime is 7972542379. The next prime is 7972542433. The reversal of 7972542421 is 1242452797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7972525521 + 16900 = 89289^2 + 130^2 .

It is a cyclic number.

It is not a de Polignac number, because 7972542421 - 2⁷ = 7972542293 is a prime.

It is a super-2 number, since 2×7972542421² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7972542491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3986271210 + 3986271211.

It is an arithmetic number, because the mean of its divisors is an integer number (3986271211).

Almost surely, 2^7972542421 is an apocalyptic number.

It is an amenable number.

7972542421 is a deficient number, since it is larger than the sum of its proper divisors (1).

7972542421 is an equidigital number, since it uses as much as digits as its factorization.

7972542421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 43.

The square root of 7972542421 is about 89289.0946364672. The cubic root of 7972542421 is about 1997.7092456406.

The spelling of 7972542421 in words is "seven billion, nine hundred seventy-two million, five hundred forty-two thousand, four hundred twenty-one".