21532004 has 12 divisors (see below), whose sum is σ = 40579644. Its totient is φ = 9937824.

The previous prime is 21531989. The next prime is 21532019. The reversal of 21532004 is 40023512.

It is an interprime number because it is at equal distance from previous prime (21531989) and next prime (21532019).

It can be written as a sum of positive squares in 2 ways, for example, as 9985600 + 11546404 = 3160^2 + 3398^2 .

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, 206987 + ... + 207090.

It is an arithmetic number, because the mean of its divisors is an integer number (3381637).

Almost surely, 2^21532004 is an apocalyptic number.

It is an amenable number.

21532004 is a deficient number, since it is larger than the sum of its proper divisors (19047640).

21532004 is a wasteful number, since it uses less digits than its factorization.

21532004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414094 (or 414092 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21532004 is about 4640.2590444931. The cubic root of 21532004 is about 278.2027918405.

Adding to 21532004 its reverse (40023512), we get a palindrome (61555516).

The spelling of 21532004 in words is "twenty-one million, five hundred thirty-two thousand, four".