21454904 has 8 divisors (see below), whose sum is σ = 40227960. Its totient is φ = 10727448.

The previous prime is 21454903. The next prime is 21454943. The reversal of 21454904 is 40945412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21454903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340924 + ... + 1340939.

It is an arithmetic number, because the mean of its divisors is an integer number (5028495).

Almost surely, 2^21454904 is an apocalyptic number.

It is an amenable number.

21454904 is a deficient number, since it is larger than the sum of its proper divisors (18773056).

21454904 is a wasteful number, since it uses less digits than its factorization.

21454904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2681869 (or 2681865 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 21454904 is about 4631.9438683991. The cubic root of 21454904 is about 277.8703396181.

The spelling of 21454904 in words is "twenty-one million, four hundred fifty-four thousand, nine hundred four".