21440763 has 6 divisors (see below), whose sum is σ = 30970004. Its totient is φ = 14293836.

The previous prime is 21440719. The next prime is 21440801. The reversal of 21440763 is 36704412.

It is not a de Polignac number, because 21440763 - 2¹⁰ = 21439739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21440863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1191145 + ... + 1191162.

Almost surely, 2^21440763 is an apocalyptic number.

21440763 is a deficient number, since it is larger than the sum of its proper divisors (9529241).

21440763 is a wasteful number, since it uses less digits than its factorization.

21440763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2382313 (or 2382310 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 21440763 is about 4630.4171518342. The cubic root of 21440763 is about 277.8092777730.

The spelling of 21440763 in words is "twenty-one million, four hundred forty thousand, seven hundred sixty-three".