21471478 has 16 divisors (see below), whose sum is σ = 36867744. Its totient is φ = 9187200.

The previous prime is 21471473. The next prime is 21471479. The reversal of 21471478 is 87417412.

It is a super-2 number, since 2×21471478² = 922048735008968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16176 + ... + 17452.

It is an arithmetic number, because the mean of its divisors is an integer number (2304234).

Almost surely, 2^21471478 is an apocalyptic number.

21471478 is a deficient number, since it is larger than the sum of its proper divisors (15396266).

21471478 is a wasteful number, since it uses less digits than its factorization.

21471478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2487.

The product of its digits is 12544, while the sum is 34.

The square root of 21471478 is about 4633.7326206850. The cubic root of 21471478 is about 277.9418731878.

The spelling of 21471478 in words is "twenty-one million, four hundred seventy-one thousand, four hundred seventy-eight".