28776461781 has 16 divisors (see below), whose sum is σ = 38550219840. Its totient is φ = 19093704960.

The previous prime is 28776461771. The next prime is 28776461821. The reversal of 28776461781 is 18716467782.

It is not a de Polignac number, because 28776461781 - 2²² = 28772267477 is a prime.

It is a super-2 number, since 2×28776461781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28776461771) 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, 564415 + ... + 613283.

It is an arithmetic number, because the mean of its divisors is an integer number (2409388740).

Almost surely, 2^28776461781 is an apocalyptic number.

It is an amenable number.

28776461781 is a deficient number, since it is larger than the sum of its proper divisors (9773758059).

28776461781 is a wasteful number, since it uses less digits than its factorization.

28776461781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49796.

The product of its digits is 6322176, while the sum is 57.

The spelling of 28776461781 in words is "twenty-eight billion, seven hundred seventy-six million, four hundred sixty-one thousand, seven hundred eighty-one".