20980621951 has 2 divisors, whose sum is σ = 20980621952. Its totient is φ = 20980621950.

The previous prime is 20980621901. The next prime is 20980621957. The reversal of 20980621951 is 15912608902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20980621951 - 2¹⁵ = 20980589183 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20980621898 and 20980621907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20980621957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10490310975 + 10490310976.

It is an arithmetic number, because the mean of its divisors is an integer number (10490310976).

Almost surely, 2^20980621951 is an apocalyptic number.

20980621951 is a deficient number, since it is larger than the sum of its proper divisors (1).

20980621951 is an equidigital number, since it uses as much as digits as its factorization.

20980621951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 43.

The spelling of 20980621951 in words is "twenty billion, nine hundred eighty million, six hundred twenty-one thousand, nine hundred fifty-one".