21496534421 has 6 divisors (see below), whose sum is σ = 21626055030. Its totient is φ = 21367784936.

The previous prime is 21496534379. The next prime is 21496534439. The reversal of 21496534421 is 12443569412.

It can be written as a sum of positive squares in only one way, i.e., 17405524900 + 4091009521 = 131930^2 + 63961^2 .

It is not a de Polignac number, because 21496534421 - 2¹⁸ = 21496272277 is a prime.

It is a super-2 number, since 2×21496534421² (a number of 21 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 (21496534481) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 357506 + ... + 413283.

It is an arithmetic number, because the mean of its divisors is an integer number (3604342505).

Almost surely, 2^21496534421 is an apocalyptic number.

It is an amenable number.

21496534421 is a deficient number, since it is larger than the sum of its proper divisors (129520609).

21496534421 is an frugal number, since it uses more digits than its factorization.

21496534421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771123 (or 770956 counting only the distinct ones).

The product of its digits is 207360, while the sum is 41.

The spelling of 21496534421 in words is "twenty-one billion, four hundred ninety-six million, five hundred thirty-four thousand, four hundred twenty-one".