21531223101 has 32 divisors (see below), whose sum is σ = 29962800000. Its totient is φ = 13736233728.

The previous prime is 21531223069. The next prime is 21531223121. The reversal of 21531223101 is 10132213512.

It is not a de Polignac number, because 21531223101 - 2⁵ = 21531223069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531223121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5250750 + ... + 5254848.

It is an arithmetic number, because the mean of its divisors is an integer number (936337500).

Almost surely, 2^21531223101 is an apocalyptic number.

It is an amenable number.

21531223101 is a deficient number, since it is larger than the sum of its proper divisors (8431576899).

21531223101 is a wasteful number, since it uses less digits than its factorization.

21531223101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4653.

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 21531223101 its reverse (10132213512), we get a palindrome (31663436613).

The spelling of 21531223101 in words is "twenty-one billion, five hundred thirty-one million, two hundred twenty-three thousand, one hundred one".