21114778 has 8 divisors (see below), whose sum is σ = 31691700. Its totient is φ = 10550880.

The previous prime is 21114767. The next prime is 21114787. The reversal of 21114778 is 87741112.

It can be written as a sum of positive squares in 2 ways, for example, as 21003889 + 110889 = 4583^2 + 333^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4398 + ... + 7846.

Almost surely, 2^21114778 is an apocalyptic number.

21114778 is a deficient number, since it is larger than the sum of its proper divisors (10576922).

21114778 is a wasteful number, since it uses less digits than its factorization.

21114778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6512.

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

The square root of 21114778 is about 4595.0819361574. The cubic root of 21114778 is about 276.3941456116.

It can be divided in two parts, 2111 and 4778, that added together give a square (6889 = 83²).

The spelling of 21114778 in words is "twenty-one million, one hundred fourteen thousand, seven hundred seventy-eight".