21541478 has 48 divisors (see below), whose sum is σ = 41368320. Its totient is φ = 8349264.

The previous prime is 21541477. The next prime is 21541493. The reversal of 21541478 is 87414512.

It is a happy number.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42575 + ... + 43077.

It is an arithmetic number, because the mean of its divisors is an integer number (861840).

Almost surely, 2^21541478 is an apocalyptic number.

21541478 is a deficient number, since it is larger than the sum of its proper divisors (19826842).

21541478 is a wasteful number, since it uses less digits than its factorization.

21541478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 554 counting only the distinct ones).

The product of its digits is 8960, while the sum is 32.

The square root of 21541478 is about 4641.2797804054. The cubic root of 21541478 is about 278.2435885816.

The spelling of 21541478 in words is "twenty-one million, five hundred forty-one thousand, four hundred seventy-eight".