21927956 has 6 divisors (see below), whose sum is σ = 38373930. Its totient is φ = 10963976.

The previous prime is 21927953. The next prime is 21928001. The reversal of 21927956 is 65972912.

It can be written as a sum of positive squares in only one way, i.e., 15476356 + 6451600 = 3934^2 + 2540^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21927953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2740991 + ... + 2740998.

It is an arithmetic number, because the mean of its divisors is an integer number (6395655).

Almost surely, 2^21927956 is an apocalyptic number.

It is an amenable number.

21927956 is a deficient number, since it is larger than the sum of its proper divisors (16445974).

21927956 is a wasteful number, since it uses less digits than its factorization.

21927956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5481993 (or 5481991 counting only the distinct ones).

The product of its digits is 68040, while the sum is 41.

The square root of 21927956 is about 4682.7295458952. The cubic root of 21927956 is about 279.8977347628.

The spelling of 21927956 in words is "twenty-one million, nine hundred twenty-seven thousand, nine hundred fifty-six".