21828012531 has 16 divisors (see below), whose sum is σ = 31856606880. Its totient is φ = 13212414720.

The previous prime is 21828012527. The next prime is 21828012571. The reversal of 21828012531 is 13521082812.

It is not a de Polignac number, because 21828012531 - 2² = 21828012527 is a prime.

It is a super-2 number, since 2×21828012531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21828012492 and 21828012501.

It is not an unprimeable number, because it can be changed into a prime (21828012511) 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, 4585266 + ... + 4590023.

It is an arithmetic number, because the mean of its divisors is an integer number (1991037930).

Almost surely, 2^21828012531 is an apocalyptic number.

21828012531 is a deficient number, since it is larger than the sum of its proper divisors (10028594349).

21828012531 is a wasteful number, since it uses less digits than its factorization.

21828012531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9175366.

The product of its (nonzero) digits is 7680, while the sum is 33.

The spelling of 21828012531 in words is "twenty-one billion, eight hundred twenty-eight million, twelve thousand, five hundred thirty-one".