20751156917 has 2 divisors, whose sum is σ = 20751156918. Its totient is φ = 20751156916.

The previous prime is 20751156887. The next prime is 20751156949. The reversal of 20751156917 is 71965115702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20710375921 + 40780996 = 143911^2 + 6386^2 .

It is a cyclic number.

It is not a de Polignac number, because 20751156917 - 2³² = 16456189621 is a prime.

It is a super-2 number, since 2×20751156917² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20751159917) 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, 10375578458 + 10375578459.

It is an arithmetic number, because the mean of its divisors is an integer number (10375578459).

Almost surely, 2^20751156917 is an apocalyptic number.

It is an amenable number.

20751156917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20751156917 is an equidigital number, since it uses as much as digits as its factorization.

20751156917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 132300, while the sum is 44.

The spelling of 20751156917 in words is "twenty billion, seven hundred fifty-one million, one hundred fifty-six thousand, nine hundred seventeen".