21722037 has 8 divisors (see below), whose sum is σ = 29579136. Its totient is φ = 14173152.

The previous prime is 21722021. The next prime is 21722047. The reversal of 21722037 is 73022712.

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

It is not a de Polignac number, because 21722037 - 2⁴ = 21722021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21721998 and 21722016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722017) 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, 76888 + ... + 77169.

It is an arithmetic number, because the mean of its divisors is an integer number (3697392).

Almost surely, 2^21722037 is an apocalyptic number.

It is an amenable number.

21722037 is a deficient number, since it is larger than the sum of its proper divisors (7857099).

21722037 is a wasteful number, since it uses less digits than its factorization.

21722037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154107.

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 21722037 is about 4660.6906140614. The cubic root of 21722037 is about 279.0188319915.

Adding to 21722037 its reverse (73022712), we get a palindrome (94744749).

The spelling of 21722037 in words is "twenty-one million, seven hundred twenty-two thousand, thirty-seven".