1285525638 has 12 divisors (see below), whose sum is σ = 2785305588. Its totient is φ = 428508540.

The previous prime is 1285525613. The next prime is 1285525643. The reversal of 1285525638 is 8365255821.

1285525638 is a `hidden beast` number, since 1 + 2 + 8 + 5 + 5 + 2 + 5 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1285525593 and 1285525602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35709028 + ... + 35709063.

It is an arithmetic number, because the mean of its divisors is an integer number (232108799).

Almost surely, 2^1285525638 is an apocalyptic number.

1285525638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1285525638 is an abundant number, since it is smaller than the sum of its proper divisors (1499779950).

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

1285525638 is a wasteful number, since it uses less digits than its factorization.

1285525638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71418099 (or 71418096 counting only the distinct ones).

The product of its digits is 576000, while the sum is 45.

The square root of 1285525638 is about 35854.2276168376. The cubic root of 1285525638 is about 1087.3271880774.

The spelling of 1285525638 in words is "one billion, two hundred eighty-five million, five hundred twenty-five thousand, six hundred thirty-eight".