21072068 has 6 divisors (see below), whose sum is σ = 36876126. Its totient is φ = 10536032.

The previous prime is 21072053. The next prime is 21072101. The reversal of 21072068 is 86027012.

It can be written as a sum of positive squares in only one way, i.e., 13410244 + 7661824 = 3662^2 + 2768^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2634005 + ... + 2634012.

It is an arithmetic number, because the mean of its divisors is an integer number (6146021).

Almost surely, 2^21072068 is an apocalyptic number.

It is an amenable number.

21072068 is a deficient number, since it is larger than the sum of its proper divisors (15804058).

21072068 is a wasteful number, since it uses less digits than its factorization.

21072068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5268021 (or 5268019 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21072068 is about 4590.4322236582. The cubic root of 21072068 is about 276.2076607034.

The spelling of 21072068 in words is "twenty-one million, seventy-two thousand, sixty-eight".