20551756685137 has 2 divisors, whose sum is σ = 20551756685138. Its totient is φ = 20551756685136.

The previous prime is 20551756685107. The next prime is 20551756685183. The reversal of 20551756685137 is 73158665715502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20543655965121 + 8100720016 = 4532511^2 + 90004^2 .

It is a cyclic number.

It is not a de Polignac number, because 20551756685137 - 2³¹ = 20549609201489 is a prime.

It is not a weakly prime, because it can be changed into another prime (20551756685107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10275878342568 + 10275878342569.

It is an arithmetic number, because the mean of its divisors is an integer number (10275878342569).

Almost surely, 2^{20551756685137} is an apocalyptic number.

It is an amenable number.

20551756685137 is a deficient number, since it is larger than the sum of its proper divisors (1).

20551756685137 is an equidigital number, since it uses as much as digits as its factorization.

20551756685137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920000, while the sum is 61.

The spelling of 20551756685137 in words is "twenty trillion, five hundred fifty-one billion, seven hundred fifty-six million, six hundred eighty-five thousand, one hundred thirty-seven".