21080076 has 48 divisors (see below), whose sum is σ = 50539776. Its totient is φ = 6836544.

The previous prime is 21080069. The next prime is 21080077. The reversal of 21080076 is 67008012.

21080076 = 269² + 270² + ... + 435².

It is not an unprimeable number, because it can be changed into a prime (21080077) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126145 + ... + 126311.

It is an arithmetic number, because the mean of its divisors is an integer number (1052912).

Almost surely, 2^21080076 is an apocalyptic number.

It is an amenable number.

21080076 is an abundant number, since it is smaller than the sum of its proper divisors (29459700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21080076 is a wasteful number, since it uses less digits than its factorization.

21080076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21080076 is about 4591.3043898221. The cubic root of 21080076 is about 276.2426452592.

Adding to 21080076 its reverse (67008012), we get a palindrome (88088088).

The spelling of 21080076 in words is "twenty-one million, eighty thousand, seventy-six".