21357033679777 has 2 divisors, whose sum is σ = 21357033679778. Its totient is φ = 21357033679776.

The previous prime is 21357033679741. The next prime is 21357033679853. The reversal of 21357033679777 is 77797633075312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21334458917776 + 22574762001 = 4618924^2 + 150249^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21357033679777 is a prime.

It is a super-2 number, since 2×21357033679777² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21357033079777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678516839888 + 10678516839889.

It is an arithmetic number, because the mean of its divisors is an integer number (10678516839889).

Almost surely, 2^{21357033679777} is an apocalyptic number.

It is an amenable number.

21357033679777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357033679777 is an equidigital number, since it uses as much as digits as its factorization.

21357033679777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 245046060, while the sum is 67.

The spelling of 21357033679777 in words is "twenty-one trillion, three hundred fifty-seven billion, thirty-three million, six hundred seventy-nine thousand, seven hundred seventy-seven".