21050550331 has 2 divisors, whose sum is σ = 21050550332. Its totient is φ = 21050550330.

The previous prime is 21050550263. The next prime is 21050550343. The reversal of 21050550331 is 13305505012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21050550331 - 2¹⁷ = 21050419259 is a prime.

It is a super-2 number, since 2×21050550331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21050550296 and 21050550305.

It is not a weakly prime, because it can be changed into another prime (21050550361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525275165 + 10525275166.

It is an arithmetic number, because the mean of its divisors is an integer number (10525275166).

Almost surely, 2^21050550331 is an apocalyptic number.

21050550331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21050550331 is an equidigital number, since it uses as much as digits as its factorization.

21050550331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 25.

The spelling of 21050550331 in words is "twenty-one billion, fifty million, five hundred fifty thousand, three hundred thirty-one".