28721335523 has 8 divisors (see below), whose sum is σ = 29759238000. Its totient is φ = 27701803168.

The previous prime is 28721335501. The next prime is 28721335529. The reversal of 28721335523 is 32553312782.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28721335523 - 2⁶ = 28721335459 is a prime.

It is a super-2 number, since 2×28721335523² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28721335529) 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, 4589348 + ... + 4595601.

It is an arithmetic number, because the mean of its divisors is an integer number (3719904750).

Almost surely, 2^28721335523 is an apocalyptic number.

28721335523 is a deficient number, since it is larger than the sum of its proper divisors (1037902477).

28721335523 is an equidigital number, since it uses as much as digits as its factorization.

28721335523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9185061.

The product of its digits is 302400, while the sum is 41.

The spelling of 28721335523 in words is "twenty-eight billion, seven hundred twenty-one million, three hundred thirty-five thousand, five hundred twenty-three".