21039277 has 8 divisors (see below), whose sum is σ = 24536000. Its totient is φ = 18033372.

The previous prime is 21039253. The next prime is 21039281. The reversal of 21039277 is 77293012.

It is a de Polignac number, because none of the positive numbers 2^k-21039277 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 (21039287) 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, 30327 + ... + 31012.

It is an arithmetic number, because the mean of its divisors is an integer number (3067000).

Almost surely, 2^21039277 is an apocalyptic number.

It is an amenable number.

21039277 is a deficient number, since it is larger than the sum of its proper divisors (3496723).

21039277 is an frugal number, since it uses more digits than its factorization.

21039277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61360 (or 61346 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 21039277 is about 4586.8591650497. The cubic root of 21039277 is about 276.0643141098.

It can be divided in two parts, 21039 and 277, that added together give a square (21316 = 146²).

The spelling of 21039277 in words is "twenty-one million, thirty-nine thousand, two hundred seventy-seven".