981021220051 has 2 divisors, whose sum is σ = 981021220052. Its totient is φ = 981021220050.

The previous prime is 981021220043. The next prime is 981021220237. The reversal of 981021220051 is 150022120189.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 981021220051 - 2³ = 981021220043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 981021219995 and 981021220022.

It is not a weakly prime, because it can be changed into another prime (981021220651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490510610025 + 490510610026.

It is an arithmetic number, because the mean of its divisors is an integer number (490510610026).

Almost surely, 2^981021220051 is an apocalyptic number.

981021220051 is a deficient number, since it is larger than the sum of its proper divisors (1).

981021220051 is an equidigital number, since it uses as much as digits as its factorization.

981021220051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 31.

The spelling of 981021220051 in words is "nine hundred eighty-one billion, twenty-one million, two hundred twenty thousand, fifty-one".