21124977 has 8 divisors (see below), whose sum is σ = 28259616. Its totient is φ = 14036832.

The previous prime is 21124973. The next prime is 21124993. The reversal of 21124977 is 77942112.

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

It is not a de Polignac number, because 21124977 - 2² = 21124973 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21124973) 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, 10548 + ... + 12389.

It is an arithmetic number, because the mean of its divisors is an integer number (3532452).

Almost surely, 2^21124977 is an apocalyptic number.

It is an amenable number.

21124977 is a deficient number, since it is larger than the sum of its proper divisors (7134639).

21124977 is a wasteful number, since it uses less digits than its factorization.

21124977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23247.

The product of its digits is 7056, while the sum is 33.

The square root of 21124977 is about 4596.1915756417. The cubic root of 21124977 is about 276.4386403590.

The spelling of 21124977 in words is "twenty-one million, one hundred twenty-four thousand, nine hundred seventy-seven".