21455432 has 8 divisors (see below), whose sum is σ = 40228950. Its totient is φ = 10727712.

The previous prime is 21455431. The next prime is 21455443. The reversal of 21455432 is 23455412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19589476 + 1865956 = 4426^2 + 1366^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21455431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340957 + ... + 1340972.

Almost surely, 2^21455432 is an apocalyptic number.

It is an amenable number.

21455432 is a deficient number, since it is larger than the sum of its proper divisors (18773518).

21455432 is a wasteful number, since it uses less digits than its factorization.

21455432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2681935 (or 2681931 counting only the distinct ones).

The product of its digits is 4800, while the sum is 26.

The square root of 21455432 is about 4632.0008635578. Note that the first 3 decimals coincide. The cubic root of 21455432 is about 277.8726190400.

The spelling of 21455432 in words is "twenty-one million, four hundred fifty-five thousand, four hundred thirty-two".