20210551391 has 2 divisors, whose sum is σ = 20210551392. Its totient is φ = 20210551390.

The previous prime is 20210551379. The next prime is 20210551397. The reversal of 20210551391 is 19315501202.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210551391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20210551397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105275695 + 10105275696.

It is an arithmetic number, because the mean of its divisors is an integer number (10105275696).

Almost surely, 2^20210551391 is an apocalyptic number.

20210551391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210551391 is an equidigital number, since it uses as much as digits as its factorization.

20210551391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2700, while the sum is 29.

The spelling of 20210551391 in words is "twenty billion, two hundred ten million, five hundred fifty-one thousand, three hundred ninety-one".