28743391021 has 8 divisors (see below), whose sum is σ = 29275784640. Its totient is φ = 28212504768.

The previous prime is 28743391009. The next prime is 28743391073. The reversal of 28743391021 is 12019334782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28743391021 is a prime.

It is a super-2 number, since 2×28743391021² (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 (28743391321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338316 + ... + 414661.

It is an arithmetic number, because the mean of its divisors is an integer number (3659473080).

Almost surely, 2^28743391021 is an apocalyptic number.

It is an amenable number.

28743391021 is a deficient number, since it is larger than the sum of its proper divisors (532393619).

28743391021 is an equidigital number, since it uses as much as digits as its factorization.

28743391021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753683.

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 28743391021 in words is "twenty-eight billion, seven hundred forty-three million, three hundred ninety-one thousand, twenty-one".