1978659 has 6 divisors (see below), whose sum is σ = 2858076. Its totient is φ = 1319100.

The previous prime is 1978631. The next prime is 1978661. The reversal of 1978659 is 9568791.

It is not a de Polignac number, because 1978659 - 2⁷ = 1978531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1978159) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 109917 + ... + 109934.

It is an arithmetic number, because the mean of its divisors is an integer number (476346).

2^1978659 is an apocalyptic number.

1978659 is a deficient number, since it is larger than the sum of its proper divisors (879417).

1978659 is a wasteful number, since it uses less digits than its factorization.

1978659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219857 (or 219854 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 1978659 is about 1406.6481436379. The cubic root of 1978659 is about 125.5423686199.

The spelling of 1978659 in words is "one million, nine hundred seventy-eight thousand, six hundred fifty-nine".