28356311581831 has 16 divisors (see below), whose sum is σ = 30592408320864. Its totient is φ = 26183386737664.

The previous prime is 28356311581823. The next prime is 28356311581837. The reversal of 28356311581831 is 13818511365382.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28356311581831 - 2³ = 28356311581823 is a prime.

It is a super-2 number, since 2×28356311581831² (a number of 28 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 (28356311581837) 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, 16835076 + ... + 18442678.

It is an arithmetic number, because the mean of its divisors is an integer number (1912025520054).

Almost surely, 2^{28356311581831} is an apocalyptic number.

28356311581831 is a deficient number, since it is larger than the sum of its proper divisors (2236096739033).

28356311581831 is a wasteful number, since it uses less digits than its factorization.

28356311581831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627250.

The product of its digits is 4147200, while the sum is 55.

The spelling of 28356311581831 in words is "twenty-eight trillion, three hundred fifty-six billion, three hundred eleven million, five hundred eighty-one thousand, eight hundred thirty-one".