21715436 has 24 divisors (see below), whose sum is σ = 38782800. Its totient is φ = 10637312.

The previous prime is 21715433. The next prime is 21715471. The reversal of 21715436 is 63451712.

It is a junction number, because it is equal to n+sod(n) for n = 21715399 and 21715408.

It is not an unprimeable number, because it can be changed into a prime (21715433) 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, 48140 + ... + 48588.

It is an arithmetic number, because the mean of its divisors is an integer number (1615950).

Almost surely, 2^21715436 is an apocalyptic number.

It is an amenable number.

21715436 is a deficient number, since it is larger than the sum of its proper divisors (17067364).

21715436 is a wasteful number, since it uses less digits than its factorization.

21715436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673 (or 671 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 21715436 is about 4659.9824034003. The cubic root of 21715436 is about 278.9905659207.

The spelling of 21715436 in words is "twenty-one million, seven hundred fifteen thousand, four hundred thirty-six".