10721601655657 has 2 divisors, whose sum is σ = 10721601655658. Its totient is φ = 10721601655656.

The previous prime is 10721601655543. The next prime is 10721601655663. The reversal of 10721601655657 is 75655610612701.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10234650298896 + 486951356761 = 3199164^2 + 697819^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10721601655657 is a prime.

It is a super-2 number, since 2×10721601655657² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (10721601655057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5360800827828 + 5360800827829.

It is an arithmetic number, because the mean of its divisors is an integer number (5360800827829).

Almost surely, 2^{10721601655657} is an apocalyptic number.

It is an amenable number.

10721601655657 is a deficient number, since it is larger than the sum of its proper divisors (1).

10721601655657 is an equidigital number, since it uses as much as digits as its factorization.

10721601655657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2646000, while the sum is 52.

The spelling of 10721601655657 in words is "ten trillion, seven hundred twenty-one billion, six hundred one million, six hundred fifty-five thousand, six hundred fifty-seven".