42724667021 has 2 divisors, whose sum is σ = 42724667022. Its totient is φ = 42724667020.

The previous prime is 42724667017. The next prime is 42724667039. The reversal of 42724667021 is 12076642724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42333062500 + 391604521 = 205750^2 + 19789^2 .

It is a cyclic number.

It is not a de Polignac number, because 42724667021 - 2² = 42724667017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42724667021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42724663021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21362333510 + 21362333511.

It is an arithmetic number, because the mean of its divisors is an integer number (21362333511).

Almost surely, 2^42724667021 is an apocalyptic number.

It is an amenable number.

42724667021 is a deficient number, since it is larger than the sum of its proper divisors (1).

42724667021 is an equidigital number, since it uses as much as digits as its factorization.

42724667021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225792, while the sum is 41.

The spelling of 42724667021 in words is "forty-two billion, seven hundred twenty-four million, six hundred sixty-seven thousand, twenty-one".