21142621 has 8 divisors (see below), whose sum is σ = 21795840. Its totient is φ = 20497968.

The previous prime is 21142613. The next prime is 21142643. The reversal of 21142621 is 12624112.

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

It is a cyclic number.

It is not a de Polignac number, because 21142621 - 2³ = 21142613 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 (21142021) 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, 3060 + ... + 7186.

It is an arithmetic number, because the mean of its divisors is an integer number (2724480).

Almost surely, 2^21142621 is an apocalyptic number.

It is an amenable number.

21142621 is a deficient number, since it is larger than the sum of its proper divisors (653219).

21142621 is a wasteful number, since it uses less digits than its factorization.

21142621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4283.

The product of its digits is 192, while the sum is 19.

The square root of 21142621 is about 4598.1105902316. The cubic root of 21142621 is about 276.5155812882.

Adding to 21142621 its reverse (12624112), we get a palindrome (33766733).

The spelling of 21142621 in words is "twenty-one million, one hundred forty-two thousand, six hundred twenty-one".