21480379 has 2 divisors, whose sum is σ = 21480380. Its totient is φ = 21480378.

The previous prime is 21480353. The next prime is 21480383. The reversal of 21480379 is 97308412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21480379 - 2¹⁵ = 21447611 is a prime.

It is a super-2 number, since 2×21480379² = 922813363967282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21480079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10740189 + 10740190.

It is an arithmetic number, because the mean of its divisors is an integer number (10740190).

Almost surely, 2^21480379 is an apocalyptic number.

21480379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21480379 is an equidigital number, since it uses as much as digits as its factorization.

21480379 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 21480379 is about 4634.6929779652. The cubic root of 21480379 is about 277.9802748111.

The spelling of 21480379 in words is "twenty-one million, four hundred eighty thousand, three hundred seventy-nine".