21478711 has 8 divisors (see below), whose sum is σ = 22960224. Its totient is φ = 20042880.

The previous prime is 21478679. The next prime is 21478729. The reversal of 21478711 is 11787412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21478711 - 2⁵ = 21478679 is a prime.

It is a super-2 number, since 2×21478711² = 922670052443042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478741) 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, 10446 + ... + 12331.

It is an arithmetic number, because the mean of its divisors is an integer number (2870028).

Almost surely, 2^21478711 is an apocalyptic number.

21478711 is a deficient number, since it is larger than the sum of its proper divisors (1481513).

21478711 is a wasteful number, since it uses less digits than its factorization.

21478711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22841.

The product of its digits is 3136, while the sum is 31.

The square root of 21478711 is about 4634.5130272770. The cubic root of 21478711 is about 277.9730793593.

The spelling of 21478711 in words is "twenty-one million, four hundred seventy-eight thousand, seven hundred eleven".