21008292881 has 2 divisors, whose sum is σ = 21008292882. Its totient is φ = 21008292880.

The previous prime is 21008292853. The next prime is 21008292917. The reversal of 21008292881 is 18829280012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20654288656 + 354004225 = 143716^2 + 18815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21008292881 is a prime.

It is a super-2 number, since 2×21008292881² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21008292281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10504146440 + 10504146441.

It is an arithmetic number, because the mean of its divisors is an integer number (10504146441).

Almost surely, 2^21008292881 is an apocalyptic number.

It is an amenable number.

21008292881 is a deficient number, since it is larger than the sum of its proper divisors (1).

21008292881 is an equidigital number, since it uses as much as digits as its factorization.

21008292881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36864, while the sum is 41.

The spelling of 21008292881 in words is "twenty-one billion, eight million, two hundred ninety-two thousand, eight hundred eighty-one".