28782901557 has 16 divisors (see below), whose sum is σ = 42752686080. Its totient is φ = 19138493376.

The previous prime is 28782901547. The next prime is 28782901577. The reversal of 28782901557 is 75510928782.

28782901557 is a `hidden beast` number, since 2 + 8 + 7 + 82 + 9 + 0 + 1 + 557 = 666.

It is not a de Polignac number, because 28782901557 - 2⁴ = 28782901541 is a prime.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28782901547) 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, 1381348 + ... + 1402029.

It is an arithmetic number, because the mean of its divisors is an integer number (2672042880).

Almost surely, 2^28782901557 is an apocalyptic number.

28782901557 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28782901557 is a deficient number, since it is larger than the sum of its proper divisors (13969784523).

28782901557 is a wasteful number, since it uses less digits than its factorization.

28782901557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783769 (or 2783763 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 28782901557 in words is "twenty-eight billion, seven hundred eighty-two million, nine hundred one thousand, five hundred fifty-seven".