1685861397 has 64 divisors (see below), whose sum is σ = 2817745920. Its totient is φ = 987336000.

The previous prime is 1685861381. The next prime is 1685861399. The reversal of 1685861397 is 7931685861.

1685861397 is a `hidden beast` number, since 16 + 8 + 5 + 8 + 613 + 9 + 7 = 666.

It is not a de Polignac number, because 1685861397 - 2⁴ = 1685861381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1685861399) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1289218 + ... + 1290524.

It is an arithmetic number, because the mean of its divisors is an integer number (44027280).

Almost surely, 2^1685861397 is an apocalyptic number.

It is an amenable number.

1685861397 is a deficient number, since it is larger than the sum of its proper divisors (1131884523).

1685861397 is a wasteful number, since it uses less digits than its factorization.

1685861397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1471 (or 1465 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 1685861397 is about 41059.2425283273. The cubic root of 1685861397 is about 1190.1653130507.

The spelling of 1685861397 in words is "one billion, six hundred eighty-five million, eight hundred sixty-one thousand, three hundred ninety-seven".