28778222461 has 4 divisors (see below), whose sum is σ = 28781034624. Its totient is φ = 28775410300.

The previous prime is 28778222411. The next prime is 28778222477. The reversal of 28778222461 is 16422287782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28778222461 - 2²³ = 28769833853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28778222411) 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, 1390675 + ... + 1411216.

It is an arithmetic number, because the mean of its divisors is an integer number (7195258656).

Almost surely, 2^28778222461 is an apocalyptic number.

It is an amenable number.

28778222461 is a deficient number, since it is larger than the sum of its proper divisors (2812163).

28778222461 is a wasteful number, since it uses less digits than its factorization.

28778222461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2812162.

The product of its digits is 1204224, while the sum is 49.

The spelling of 28778222461 in words is "twenty-eight billion, seven hundred seventy-eight million, two hundred twenty-two thousand, four hundred sixty-one".