28621457191 has 4 divisors (see below), whose sum is σ = 28622281072. Its totient is φ = 28620633312.

The previous prime is 28621457167. The next prime is 28621457197. The reversal of 28621457191 is 19175412682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28621457191 is a prime.

It is a super-2 number, since 2×28621457191² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28621457197) 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, 357426 + ... + 430111.

It is an arithmetic number, because the mean of its divisors is an integer number (7155570268).

Almost surely, 2^28621457191 is an apocalyptic number.

28621457191 is a deficient number, since it is larger than the sum of its proper divisors (823881).

28621457191 is an equidigital number, since it uses as much as digits as its factorization.

28621457191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823880.

The product of its digits is 241920, while the sum is 46.

The spelling of 28621457191 in words is "twenty-eight billion, six hundred twenty-one million, four hundred fifty-seven thousand, one hundred ninety-one".