1285681398 has 32 divisors (see below), whose sum is σ = 2732019840. Its totient is φ = 402206400.

The previous prime is 1285681387. The next prime is 1285681399. The reversal of 1285681398 is 8931865821.

It is a self number, because there is not a number n which added to its sum of digits gives 1285681398.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285681399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40503 + ... + 64898.

It is an arithmetic number, because the mean of its divisors is an integer number (85375620).

Almost surely, 2^1285681398 is an apocalyptic number.

1285681398 is an abundant number, since it is smaller than the sum of its proper divisors (1446338442).

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

1285681398 is a wasteful number, since it uses less digits than its factorization.

1285681398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105532.

The product of its digits is 829440, while the sum is 51.

The square root of 1285681398 is about 35856.3996798340. The cubic root of 1285681398 is about 1087.3711014355.

The spelling of 1285681398 in words is "one billion, two hundred eighty-five million, six hundred eighty-one thousand, three hundred ninety-eight".