21077480 has 16 divisors (see below), whose sum is σ = 47424420. Its totient is φ = 8430976.

The previous prime is 21077477. The next prime is 21077527. The reversal of 21077480 is 8477012.

It can be written as a sum of positive squares in 2 ways, for example, as 17757796 + 3319684 = 4214^2 + 1822^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263429 + ... + 263508.

Almost surely, 2^21077480 is an apocalyptic number.

21077480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21077480 is an abundant number, since it is smaller than the sum of its proper divisors (26346940).

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

21077480 is a wasteful number, since it uses less digits than its factorization.

21077480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526948 (or 526944 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 21077480 is about 4591.0216727870. The cubic root of 21077480 is about 276.2313050827.

The spelling of 21077480 in words is "twenty-one million, seventy-seven thousand, four hundred eighty".