21046478 has 16 divisors (see below), whose sum is σ = 32144784. Its totient is φ = 10333440.

The previous prime is 21046477. The next prime is 21046507. The reversal of 21046478 is 87464012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21046477) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30113 + ... + 30803.

It is an arithmetic number, because the mean of its divisors is an integer number (2009049).

Almost surely, 2^21046478 is an apocalyptic number.

21046478 is a deficient number, since it is larger than the sum of its proper divisors (11098306).

21046478 is a wasteful number, since it uses less digits than its factorization.

21046478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947.

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 21046478 is about 4587.6440576836. The cubic root of 21046478 is about 276.0958061990.

The spelling of 21046478 in words is "twenty-one million, forty-six thousand, four hundred seventy-eight".