21040077 has 8 divisors (see below), whose sum is σ = 28472416. Its totient is φ = 13817232.

The previous prime is 21040073. The next prime is 21040079. The reversal of 21040077 is 77004012.

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

It is not a de Polignac number, because 21040077 - 2² = 21040073 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 (21040073) 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 7 ways as a sum of consecutive naturals, for example, 52138 + ... + 52539.

It is an arithmetic number, because the mean of its divisors is an integer number (3559052).

Almost surely, 2^21040077 is an apocalyptic number.

It is an amenable number.

21040077 is a deficient number, since it is larger than the sum of its proper divisors (7432339).

21040077 is a wasteful number, since it uses less digits than its factorization.

21040077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104747.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 21040077 is about 4586.9463698631. The cubic root of 21040077 is about 276.0678130996.

Adding to 21040077 its reverse (77004012), we get a palindrome (98044089).

The spelling of 21040077 in words is "twenty-one million, forty thousand, seventy-seven".