21011478 has 16 divisors (see below), whose sum is σ = 42087936. Its totient is φ = 6993000.

The previous prime is 21011453. The next prime is 21011503. The reversal of 21011478 is 87411012.

It is an interprime number because it is at equal distance from previous prime (21011453) and next prime (21011503).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2175 + ... + 6837.

It is an arithmetic number, because the mean of its divisors is an integer number (2630496).

Almost surely, 2^21011478 is an apocalyptic number.

21011478 is an abundant number, since it is smaller than the sum of its proper divisors (21076458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011478 is a wasteful number, since it uses less digits than its factorization.

21011478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5419.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 21011478 is about 4583.8278763496. The cubic root of 21011478 is about 275.9426734540.

The spelling of 21011478 in words is "twenty-one million, eleven thousand, four hundred seventy-eight".