21073077 has 6 divisors (see below), whose sum is σ = 30438902. Its totient is φ = 14048712.

The previous prime is 21073069. The next prime is 21073093. The reversal of 21073077 is 77037012.

It can be written as a sum of positive squares in only one way, i.e., 14447601 + 6625476 = 3801^2 + 2574^2 .

It is not a de Polignac number, because 21073077 - 2³ = 21073069 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21073077.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1170718 + ... + 1170735.

Almost surely, 2^21073077 is an apocalyptic number.

It is an amenable number.

21073077 is a deficient number, since it is larger than the sum of its proper divisors (9365825).

21073077 is a wasteful number, since it uses less digits than its factorization.

21073077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2341459 (or 2341456 counting only the distinct ones).

The product of its (nonzero) digits is 2058, while the sum is 27.

The square root of 21073077 is about 4590.5421248476. The cubic root of 21073077 is about 276.2120692105.

It can be divided in two parts, 2107 and 3077, that added together give a square (5184 = 72²).

The spelling of 21073077 in words is "twenty-one million, seventy-three thousand, seventy-seven".