21402613 has 8 divisors (see below), whose sum is σ = 22057632. Its totient is φ = 20751696.

The previous prime is 21402593. The next prime is 21402637. The reversal of 21402613 is 31620412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21402613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402653) 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, 12006 + ... + 13672.

It is an arithmetic number, because the mean of its divisors is an integer number (2757204).

Almost surely, 2^21402613 is an apocalyptic number.

It is an amenable number.

21402613 is a deficient number, since it is larger than the sum of its proper divisors (655019).

21402613 is a wasteful number, since it uses less digits than its factorization.

21402613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2051.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21402613 is about 4626.2958184708. The cubic root of 21402613 is about 277.6444093217.

It can be divided in two parts, 2140 and 2613, that added together give a triangular number (4753 = T₉₇).

The spelling of 21402613 in words is "twenty-one million, four hundred two thousand, six hundred thirteen".