1985197557 has 32 divisors (see below), whose sum is σ = 3069767680. Its totient is φ = 1117696320.

The previous prime is 1985197537. The next prime is 1985197567. The reversal of 1985197557 is 7557915891.

It is not a de Polignac number, because 1985197557 - 2¹² = 1985193461 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1985197497 and 1985197506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985197507) 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, 1065807 + ... + 1067667.

It is an arithmetic number, because the mean of its divisors is an integer number (95930240).

Almost surely, 2^1985197557 is an apocalyptic number.

It is an amenable number.

1985197557 is a deficient number, since it is larger than the sum of its proper divisors (1084570123).

1985197557 is a wasteful number, since it uses less digits than its factorization.

1985197557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2593.

The product of its digits is 3969000, while the sum is 57.

The square root of 1985197557 is about 44555.5558488501. Note that the first 3 decimals coincide. The cubic root of 1985197557 is about 1256.8050315025.

The spelling of 1985197557 in words is "one billion, nine hundred eighty-five million, one hundred ninety-seven thousand, five hundred fifty-seven".