1268128551 has 8 divisors (see below), whose sum is σ = 1691933040. Its totient is φ = 844871552.

The previous prime is 1268128541. The next prime is 1268128591. The reversal of 1268128551 is 1558218621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1268128551 - 2⁶ = 1268128487 is a prime.

It is a super-2 number, since 2×1268128551² = 3216300043722719202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1268128541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131436 + ... + 140753.

It is an arithmetic number, because the mean of its divisors is an integer number (211491630).

Almost surely, 2^1268128551 is an apocalyptic number.

1268128551 is a deficient number, since it is larger than the sum of its proper divisors (423804489).

1268128551 is a wasteful number, since it uses less digits than its factorization.

1268128551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273745.

The product of its digits is 38400, while the sum is 39.

The square root of 1268128551 is about 35610.7926196539. The cubic root of 1268128551 is about 1082.3999416110.

The spelling of 1268128551 in words is "one billion, two hundred sixty-eight million, one hundred twenty-eight thousand, five hundred fifty-one".