42621728 has 12 divisors (see below), whose sum is σ = 83911590. Its totient is φ = 21310848.

The previous prime is 42621727. The next prime is 42621749. The reversal of 42621728 is 82712624.

It can be written as a sum of positive squares in only one way, i.e., 41113744 + 1507984 = 6412^2 + 1228^2 .

It is a super-2 number, since 2×42621728² = 3633223395411968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 1331929 = 42621728 / (4 + 2 + 6 + 2 + 1 + 7 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 42621694 and 42621703.

It is not an unprimeable number, because it can be changed into a prime (42621727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665933 + ... + 665996.

Almost surely, 2^42621728 is an apocalyptic number.

It is an amenable number.

42621728 is a deficient number, since it is larger than the sum of its proper divisors (41289862).

42621728 is a wasteful number, since it uses less digits than its factorization.

42621728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331939 (or 1331931 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 42621728 is about 6528.5318410804. The cubic root of 42621728 is about 349.3094629819.

The spelling of 42621728 in words is "forty-two million, six hundred twenty-one thousand, seven hundred twenty-eight".