78905650987 has 4 divisors (see below), whose sum is σ = 80016998256. Its totient is φ = 77794303720.

The previous prime is 78905650979. The next prime is 78905651003.

78905650987 is nontrivially palindromic in base 10.

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 78905650987 - 2³ = 78905650979 is a prime.

It is a super-2 number, since 2×78905650987² (a number of 23 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78905650907) 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, 555673528 + ... + 555673669.

It is an arithmetic number, because the mean of its divisors is an integer number (20004249564).

Almost surely, 2^78905650987 is an apocalyptic number.

78905650987 is a deficient number, since it is larger than the sum of its proper divisors (1111347269).

78905650987 is a wasteful number, since it uses less digits than its factorization.

78905650987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111347268.

The product of its (nonzero) digits is 38102400, while the sum is 64.

The spelling of 78905650987 in words is "seventy-eight billion, nine hundred five million, six hundred fifty thousand, nine hundred eighty-seven".