21503479 has 2 divisors, whose sum is σ = 21503480. Its totient is φ = 21503478.

The previous prime is 21503467. The next prime is 21503527. The reversal of 21503479 is 97430512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21503479 is a prime.

It is equal to p_1359814 and since 21503479 and 1359814 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21503479.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21501479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751739 + 10751740.

It is an arithmetic number, because the mean of its divisors is an integer number (10751740).

Almost surely, 2^21503479 is an apocalyptic number.

21503479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21503479 is an equidigital number, since it uses as much as digits as its factorization.

21503479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21503479 is about 4637.1843827909. The cubic root of 21503479 is about 278.0798857768.

The spelling of 21503479 in words is "twenty-one million, five hundred three thousand, four hundred seventy-nine".