7021720501 has 2 divisors, whose sum is σ = 7021720502. Its totient is φ = 7021720500.

The previous prime is 7021720483. The next prime is 7021720571. The reversal of 7021720501 is 1050271207.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5877522225 + 1144198276 = 76665^2 + 33826^2 .

It is a cyclic number.

It is not a de Polignac number, because 7021720501 - 2⁵ = 7021720469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7021720571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3510860250 + 3510860251.

It is an arithmetic number, because the mean of its divisors is an integer number (3510860251).

Almost surely, 2^7021720501 is an apocalyptic number.

It is an amenable number.

7021720501 is a deficient number, since it is larger than the sum of its proper divisors (1).

7021720501 is an equidigital number, since it uses as much as digits as its factorization.

7021720501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 7021720501 is about 83795.7069365728. The cubic root of 7021720501 is about 1914.9077028780.

Adding to 7021720501 its reverse (1050271207), we get a palindrome (8071991708).

The spelling of 7021720501 in words is "seven billion, twenty-one million, seven hundred twenty thousand, five hundred one".