28778149917 has 24 divisors (see below), whose sum is σ = 45618955200. Its totient is φ = 17336854080.

The previous prime is 28778149903. The next prime is 28778149931. The reversal of 28778149917 is 71994187782.

It is an interprime number because it is at equal distance from previous prime (28778149903) and next prime (28778149931).

It is not a de Polignac number, because 28778149917 - 2²³ = 28769761309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28778149937) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 853792 + ... + 886857.

It is an arithmetic number, because the mean of its divisors is an integer number (1900789800).

Almost surely, 2^28778149917 is an apocalyptic number.

It is an amenable number.

28778149917 is a deficient number, since it is larger than the sum of its proper divisors (16840805283).

28778149917 is a wasteful number, since it uses less digits than its factorization.

28778149917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740833 (or 1740830 counting only the distinct ones).

The product of its digits is 14224896, while the sum is 63.

The spelling of 28778149917 in words is "twenty-eight billion, seven hundred seventy-eight million, one hundred forty-nine thousand, nine hundred seventeen".