268916521 has 2 divisors, whose sum is σ = 268916522. Its totient is φ = 268916520.

The previous prime is 268916509. The next prime is 268916551. The reversal of 268916521 is 125619862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 257281600 + 11634921 = 16040^2 + 3411^2 .

It is a cyclic number.

It is not a de Polignac number, because 268916521 - 2¹¹ = 268914473 is a prime.

It is a super-4 number, since 4×268916521⁴ (a number of 35 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (268916551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134458260 + 134458261.

It is an arithmetic number, because the mean of its divisors is an integer number (134458261).

Almost surely, 2^268916521 is an apocalyptic number.

It is an amenable number.

268916521 is a deficient number, since it is larger than the sum of its proper divisors (1).

268916521 is an equidigital number, since it uses as much as digits as its factorization.

268916521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 268916521 is about 16398.6743671554. The cubic root of 268916521 is about 645.4646980730.

The spelling of 268916521 in words is "two hundred sixty-eight million, nine hundred sixteen thousand, five hundred twenty-one".