21163478 has 16 divisors (see below), whose sum is σ = 36397824. Its totient is φ = 9040680.

The previous prime is 21163469. The next prime is 21163481. The reversal of 21163478 is 87436112.

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, 2351 + ... + 6917.

It is an arithmetic number, because the mean of its divisors is an integer number (2274864).

Almost surely, 2^21163478 is an apocalyptic number.

21163478 is a deficient number, since it is larger than the sum of its proper divisors (15234346).

21163478 is a wasteful number, since it uses less digits than its factorization.

21163478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4907.

The product of its digits is 8064, while the sum is 32.

The square root of 21163478 is about 4600.3780279451. The cubic root of 21163478 is about 276.6064780926.

The spelling of 21163478 in words is "twenty-one million, one hundred sixty-three thousand, four hundred seventy-eight".