20910291973 has 2 divisors, whose sum is σ = 20910291974. Its totient is φ = 20910291972.

The previous prime is 20910291959. The next prime is 20910292027. The reversal of 20910291973 is 37919201902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18995179329 + 1915112644 = 137823^2 + 43762^2 .

It is a cyclic number.

It is not a de Polignac number, because 20910291973 - 2³³ = 12320357381 is a prime.

It is a super-2 number, since 2×20910291973² (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 (20910291373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10455145986 + 10455145987.

It is an arithmetic number, because the mean of its divisors is an integer number (10455145987).

Almost surely, 2^20910291973 is an apocalyptic number.

It is an amenable number.

20910291973 is a deficient number, since it is larger than the sum of its proper divisors (1).

20910291973 is an equidigital number, since it uses as much as digits as its factorization.

20910291973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 43.

The spelling of 20910291973 in words is "twenty billion, nine hundred ten million, two hundred ninety-one thousand, nine hundred seventy-three".