1971855 has 24 divisors (see below), whose sum is σ = 3538080. Its totient is φ = 1014720.

The previous prime is 1971833. The next prime is 1971857. The reversal of 1971855 is 5581791.

It is not a de Polignac number, because 1971855 - 2⁷ = 1971727 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 550 + ... + 2060.

It is an arithmetic number, because the mean of its divisors is an integer number (147420).

2^1971855 is an apocalyptic number.

1971855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1971855 is a deficient number, since it is larger than the sum of its proper divisors (1566225).

1971855 is a wasteful number, since it uses less digits than its factorization.

1971855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551 (or 1548 counting only the distinct ones).

The product of its digits is 12600, while the sum is 36.

The square root of 1971855 is about 1404.2275456635. The cubic root of 1971855 is about 125.3983028242.

The spelling of 1971855 in words is "one million, nine hundred seventy-one thousand, eight hundred fifty-five".