21948277 has 4 divisors (see below), whose sum is σ = 23636620. Its totient is φ = 20259936.

The previous prime is 21948263. The next prime is 21948293. The reversal of 21948277 is 77284912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11229201 + 10719076 = 3351^2 + 3274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21948277 - 2⁷ = 21948149 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 (21948077) 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, 844152 + ... + 844177.

It is an arithmetic number, because the mean of its divisors is an integer number (5909155).

Almost surely, 2^21948277 is an apocalyptic number.

It is an amenable number.

21948277 is a deficient number, since it is larger than the sum of its proper divisors (1688343).

21948277 is a wasteful number, since it uses less digits than its factorization.

21948277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1688342.

The product of its digits is 56448, while the sum is 40.

The square root of 21948277 is about 4684.8988249481. The cubic root of 21948277 is about 279.9841700234.

The spelling of 21948277 in words is "twenty-one million, nine hundred forty-eight thousand, two hundred seventy-seven".