21004337252 has 6 divisors (see below), whose sum is σ = 36757590198. Its totient is φ = 10502168624.

The previous prime is 21004337243. The next prime is 21004337261. The reversal of 21004337252 is 25273340012.

It is an interprime number because it is at equal distance from previous prime (21004337243) and next prime (21004337261).

It can be written as a sum of positive squares in only one way, i.e., 19503239716 + 1501097536 = 139654^2 + 38744^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625542153 + ... + 2625542160.

It is an arithmetic number, because the mean of its divisors is an integer number (6126265033).

Almost surely, 2^21004337252 is an apocalyptic number.

It is an amenable number.

21004337252 is a deficient number, since it is larger than the sum of its proper divisors (15753252946).

21004337252 is a wasteful number, since it uses less digits than its factorization.

21004337252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5251084317 (or 5251084315 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 29.

Adding to 21004337252 its reverse (25273340012), we get a palindrome (46277677264).

The spelling of 21004337252 in words is "twenty-one billion, four million, three hundred thirty-seven thousand, two hundred fifty-two".