21250143391 has 2 divisors, whose sum is σ = 21250143392. Its totient is φ = 21250143390.

The previous prime is 21250143377. The next prime is 21250143401. The reversal of 21250143391 is 19334105212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21250143391 - 2¹¹ = 21250141343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250143311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625071695 + 10625071696.

It is an arithmetic number, because the mean of its divisors is an integer number (10625071696).

Almost surely, 2^21250143391 is an apocalyptic number.

21250143391 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250143391 is an equidigital number, since it uses as much as digits as its factorization.

21250143391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 21250143391 in words is "twenty-one billion, two hundred fifty million, one hundred forty-three thousand, three hundred ninety-one".