1978855 has 8 divisors (see below), whose sum is σ = 2391264. Its totient is φ = 1572000.

The previous prime is 1978853. The next prime is 1978877. The reversal of 1978855 is 5588791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1978855 - 2¹ = 1978853 is a prime.

It is a super-2 number, since 2×1978855² = 7831734222050, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 556 + ... + 2065.

It is an arithmetic number, because the mean of its divisors is an integer number (298908).

2^1978855 is an apocalyptic number.

1978855 is a deficient number, since it is larger than the sum of its proper divisors (412409).

1978855 is a wasteful number, since it uses less digits than its factorization.

1978855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2777.

The product of its digits is 100800, while the sum is 43.

The square root of 1978855 is about 1406.7178110765. The cubic root of 1978855 is about 125.5465137660.

The spelling of 1978855 in words is "one million, nine hundred seventy-eight thousand, eight hundred fifty-five".