720021902857 has 2 divisors, whose sum is σ = 720021902858. Its totient is φ = 720021902856.

The previous prime is 720021902851. The next prime is 720021902861. The reversal of 720021902857 is 758209120027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 497369099536 + 222652803321 = 705244^2 + 471861^2 .

It is a cyclic number.

It is not a de Polignac number, because 720021902857 - 2¹⁹ = 720021378569 is a prime.

It is not a weakly prime, because it can be changed into another prime (720021902851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360010951428 + 360010951429.

It is an arithmetic number, because the mean of its divisors is an integer number (360010951429).

Almost surely, 2^720021902857 is an apocalyptic number.

It is an amenable number.

720021902857 is a deficient number, since it is larger than the sum of its proper divisors (1).

720021902857 is an equidigital number, since it uses as much as digits as its factorization.

720021902857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 141120, while the sum is 43.

The spelling of 720021902857 in words is "seven hundred twenty billion, twenty-one million, nine hundred two thousand, eight hundred fifty-seven".