2620654307981 has 2 divisors, whose sum is σ = 2620654307982. Its totient is φ = 2620654307980.

The previous prime is 2620654307963. The next prime is 2620654308011. The reversal of 2620654307981 is 1897034560262.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1445142983881 + 1175511324100 = 1202141^2 + 1084210^2 .

It is a cyclic number.

It is not a de Polignac number, because 2620654307981 - 2²⁶ = 2620587199117 is a prime.

It is a super-2 number, since 2×2620654307981² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2620654307951) 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, 1310327153990 + 1310327153991.

It is an arithmetic number, because the mean of its divisors is an integer number (1310327153991).

It is a 1-persistent number, because it is pandigital, but 2⋅2620654307981 = 5241308615962 is not.

Almost surely, 2^{2620654307981} is an apocalyptic number.

It is an amenable number.

2620654307981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2620654307981 is an equidigital number, since it uses as much as digits as its factorization.

2620654307981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4354560, while the sum is 53.

The spelling of 2620654307981 in words is "two trillion, six hundred twenty billion, six hundred fifty-four million, three hundred seven thousand, nine hundred eighty-one".