21016977 has 8 divisors (see below), whose sum is σ = 28926720. Its totient is φ = 13559280.

The previous prime is 21016949. The next prime is 21016979. The reversal of 21016977 is 77961012.

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

It is not a de Polignac number, because 21016977 - 2¹⁵ = 20984209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21016979) 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, 112902 + ... + 113087.

It is an arithmetic number, because the mean of its divisors is an integer number (3615840).

Almost surely, 2^21016977 is an apocalyptic number.

It is an amenable number.

21016977 is a deficient number, since it is larger than the sum of its proper divisors (7909743).

21016977 is a wasteful number, since it uses less digits than its factorization.

21016977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226023.

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 21016977 is about 4584.4276632967. The cubic root of 21016977 is about 275.9667440502.

Adding to 21016977 its reverse (77961012), we get a palindrome (98977989).

The spelling of 21016977 in words is "twenty-one million, sixteen thousand, nine hundred seventy-seven".