1978858609 has 16 divisors (see below), whose sum is σ = 2436835968. Its totient is φ = 1564843392.

The previous prime is 1978858603. The next prime is 1978858639. The reversal of 1978858609 is 9068588791.

It is not a de Polignac number, because 1978858609 - 2¹⁵ = 1978825841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1978858603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 204294 + ... + 213760.

It is an arithmetic number, because the mean of its divisors is an integer number (152302248).

Almost surely, 2^1978858609 is an apocalyptic number.

It is an amenable number.

1978858609 is a deficient number, since it is larger than the sum of its proper divisors (457977359).

1978858609 is a wasteful number, since it uses less digits than its factorization.

1978858609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11784.

The product of its (nonzero) digits is 8709120, while the sum is 61.

The square root of 1978858609 is about 44484.3636461173. The cubic root of 1978858609 is about 1255.4659008914.

The spelling of 1978858609 in words is "one billion, nine hundred seventy-eight million, eight hundred fifty-eight thousand, six hundred nine".