1285988881 has 2 divisors, whose sum is σ = 1285988882. Its totient is φ = 1285988880.

The previous prime is 1285988833. The next prime is 1285988947. The reversal of 1285988881 is 1888895821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1274490000 + 11498881 = 35700^2 + 3391^2 .

It is a cyclic number.

It is not a de Polignac number, because 1285988881 - 2²¹ = 1283891729 is a prime.

It is a super-2 number, since 2×1285988881² = 3307534804111264322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1285988801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 642994440 + 642994441.

It is an arithmetic number, because the mean of its divisors is an integer number (642994441).

Almost surely, 2^1285988881 is an apocalyptic number.

It is an amenable number.

1285988881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1285988881 is an equidigital number, since it uses as much as digits as its factorization.

1285988881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2949120, while the sum is 58.

The square root of 1285988881 is about 35860.6871239244. The cubic root of 1285988881 is about 1087.4577795913.

The spelling of 1285988881 in words is "one billion, two hundred eighty-five million, nine hundred eighty-eight thousand, eight hundred eighty-one".