1978099 has 4 divisors (see below), whose sum is σ = 1983240. Its totient is φ = 1972960.

The previous prime is 1978091. The next prime is 1978111. The reversal of 1978099 is 9908791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1978099 - 2³ = 1978091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1942 + ... + 2779.

It is an arithmetic number, because the mean of its divisors is an integer number (495810).

2^1978099 is an apocalyptic number.

1978099 is a deficient number, since it is larger than the sum of its proper divisors (5141).

1978099 is an equidigital number, since it uses as much as digits as its factorization.

1978099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5140.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 1978099 is about 1406.4490747979. The cubic root of 1978099 is about 125.5305238369.

The spelling of 1978099 in words is "one million, nine hundred seventy-eight thousand, ninety-nine".