1978876636 has 36 divisors (see below), whose sum is σ = 4013180136. Its totient is φ = 846572800.

The previous prime is 1978876633. The next prime is 1978876637. The reversal of 1978876636 is 6366788791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978876631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65095 + ... + 90526.

It is an arithmetic number, because the mean of its divisors is an integer number (111477226).

Almost surely, 2^1978876636 is an apocalyptic number.

It is an amenable number.

1978876636 is an abundant number, since it is smaller than the sum of its proper divisors (2034303500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978876636 is a wasteful number, since it uses less digits than its factorization.

1978876636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155670 (or 155651 counting only the distinct ones).

The product of its digits is 18289152, while the sum is 61.

The square root of 1978876636 is about 44484.5662674146. The cubic root of 1978876636 is about 1255.4697132262.

The spelling of 1978876636 in words is "one billion, nine hundred seventy-eight million, eight hundred seventy-six thousand, six hundred thirty-six".