21573404 has 6 divisors (see below), whose sum is σ = 37753464. Its totient is φ = 10786700.

The previous prime is 21573371. The next prime is 21573407. The reversal of 21573404 is 40437512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21573407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2696672 + ... + 2696679.

It is an arithmetic number, because the mean of its divisors is an integer number (6292244).

Almost surely, 2^21573404 is an apocalyptic number.

It is an amenable number.

21573404 is a deficient number, since it is larger than the sum of its proper divisors (16180060).

21573404 is a wasteful number, since it uses less digits than its factorization.

21573404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5393355 (or 5393353 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21573404 is about 4644.7178601073. The cubic root of 21573404 is about 278.3809796481.

The spelling of 21573404 in words is "twenty-one million, five hundred seventy-three thousand, four hundred four".