21620726 has 8 divisors (see below), whose sum is σ = 32453784. Its totient is φ = 10802800.

The previous prime is 21620723. The next prime is 21620737. The reversal of 21620726 is 62702612.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21620695 and 21620704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1001 + ... + 6651.

It is an arithmetic number, because the mean of its divisors is an integer number (4056723).

Almost surely, 2^21620726 is an apocalyptic number.

21620726 is a deficient number, since it is larger than the sum of its proper divisors (10833058).

21620726 is a wasteful number, since it uses less digits than its factorization.

21620726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7566.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21620726 is about 4649.8092433991. The cubic root of 21620726 is about 278.5843770695.

The spelling of 21620726 in words is "twenty-one million, six hundred twenty thousand, seven hundred twenty-six".