1978654787 has 8 divisors (see below), whose sum is σ = 2095501056. Its totient is φ = 1864376712.

The previous prime is 1978654751. The next prime is 1978654819. The reversal of 1978654787 is 7874568791.

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

It is a cyclic number.

It is not a de Polignac number, because 1978654787 - 2¹⁰ = 1978653763 is a prime.

It is a super-2 number, since 2×1978654787² = 7830149532236030738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978654187) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 640463 + ... + 643544.

It is an arithmetic number, because the mean of its divisors is an integer number (261937632).

Almost surely, 2^1978654787 is an apocalyptic number.

1978654787 is a deficient number, since it is larger than the sum of its proper divisors (116846269).

1978654787 is a wasteful number, since it uses less digits than its factorization.

1978654787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1284097.

The product of its digits is 23708160, while the sum is 62.

The square root of 1978654787 is about 44482.0726473037. The cubic root of 1978654787 is about 1255.4227951745.

The spelling of 1978654787 in words is "one billion, nine hundred seventy-eight million, six hundred fifty-four thousand, seven hundred eighty-seven".