1281386988 has 36 divisors (see below), whose sum is σ = 3701785360. Its totient is φ = 366110496.

The previous prime is 1281386987. The next prime is 1281387001. The reversal of 1281386988 is 8896831821.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1281386988² = 3283905226031424288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1281386987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2542183 + ... + 2542686.

Almost surely, 2^1281386988 is an apocalyptic number.

1281386988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1281386988 is an abundant number, since it is smaller than the sum of its proper divisors (2420398372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1281386988 is a wasteful number, since it uses less digits than its factorization.

1281386988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5084886 (or 5084881 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 54.

The square root of 1281386988 is about 35796.4661384333. The cubic root of 1281386988 is about 1086.1590784744.

The spelling of 1281386988 in words is "one billion, two hundred eighty-one million, three hundred eighty-six thousand, nine hundred eighty-eight".