21511713 has 8 divisors (see below), whose sum is σ = 29075488. Its totient is φ = 14144544.

The previous prime is 21511663. The next prime is 21511717. The reversal of 21511713 is 31711512.

It is a happy number.

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

It is not a de Polignac number, because 21511713 - 2¹² = 21507617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21511713.

It is not an unprimeable number, because it can be changed into a prime (21511717) 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, 48895 + ... + 49332.

It is an arithmetic number, because the mean of its divisors is an integer number (3634436).

Almost surely, 2^21511713 is an apocalyptic number.

It is an amenable number.

21511713 is a deficient number, since it is larger than the sum of its proper divisors (7563775).

21511713 is an equidigital number, since it uses as much as digits as its factorization.

21511713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98303.

The product of its digits is 210, while the sum is 21.

The square root of 21511713 is about 4638.0721210434. The cubic root of 21511713 is about 278.1153748805.

The spelling of 21511713 in words is "twenty-one million, five hundred eleven thousand, seven hundred thirteen".