1985705918 has 16 divisors (see below), whose sum is σ = 3405265920. Its totient is φ = 850717176.

The previous prime is 1985705849. The next prime is 1985705933. The reversal of 1985705918 is 8195075891.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1985705918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18863 + ... + 65781.

It is an arithmetic number, because the mean of its divisors is an integer number (212829120).

Almost surely, 2^1985705918 is an apocalyptic number.

1985705918 is a deficient number, since it is larger than the sum of its proper divisors (1419560002).

1985705918 is a wasteful number, since it uses less digits than its factorization.

1985705918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49951.

The product of its (nonzero) digits is 907200, while the sum is 53.

The square root of 1985705918 is about 44561.2602828959. The cubic root of 1985705918 is about 1256.9123014535.

The spelling of 1985705918 in words is "one billion, nine hundred eighty-five million, seven hundred five thousand, nine hundred eighteen".