21216040432 has 20 divisors (see below), whose sum is σ = 41174493136. Its totient is φ = 10590364800.

The previous prime is 21216040421. The next prime is 21216040519. The reversal of 21216040432 is 23404061212.

It is a happy number.

It is a super-2 number, since 2×21216040432² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21216040397 and 21216040406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1093548 + ... + 1112779.

Almost surely, 2^21216040432 is an apocalyptic number.

It is an amenable number.

21216040432 is a deficient number, since it is larger than the sum of its proper divisors (19958452704).

21216040432 is a wasteful number, since it uses less digits than its factorization.

21216040432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2206936 (or 2206930 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The spelling of 21216040432 in words is "twenty-one billion, two hundred sixteen million, forty thousand, four hundred thirty-two".