1285681397 has 32 divisors (see below), whose sum is σ = 1736792064. Its totient is φ = 919108800.

The previous prime is 1285681387. The next prime is 1285681399. The reversal of 1285681397 is 7931865821.

It is a cyclic number.

It is not a de Polignac number, because 1285681397 - 2⁶ = 1285681333 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 31 ways as a sum of consecutive naturals, for example, 163322 + ... + 171012.

It is an arithmetic number, because the mean of its divisors is an integer number (54274752).

Almost surely, 2^1285681397 is an apocalyptic number.

It is an amenable number.

1285681397 is a deficient number, since it is larger than the sum of its proper divisors (451110667).

1285681397 is a wasteful number, since it uses less digits than its factorization.

1285681397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7889.

The product of its digits is 725760, while the sum is 50.

The square root of 1285681397 is about 35856.3996658895. The cubic root of 1285681397 is about 1087.3711011536.

The spelling of 1285681397 in words is "one billion, two hundred eighty-five million, six hundred eighty-one thousand, three hundred ninety-seven".