21148756 has 12 divisors (see below), whose sum is σ = 38010868. Its totient is φ = 10288512.

The previous prime is 21148723. The next prime is 21148759. The reversal of 21148756 is 65784112.

It can be written as a sum of positive squares in 2 ways, for example, as 19660356 + 1488400 = 4434^2 + 1220^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21148759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71301 + ... + 71596.

Almost surely, 2^21148756 is an apocalyptic number.

It is an amenable number.

21148756 is a deficient number, since it is larger than the sum of its proper divisors (16862112).

21148756 is a wasteful number, since it uses less digits than its factorization.

21148756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142938 (or 142936 counting only the distinct ones).

The product of its digits is 13440, while the sum is 34.

The square root of 21148756 is about 4598.7776636841. Note that the first 3 decimals coincide. The cubic root of 21148756 is about 276.5423244094.

It can be divided in two parts, 21148 and 756, that added together give a square (21904 = 148²).

The spelling of 21148756 in words is "twenty-one million, one hundred forty-eight thousand, seven hundred fifty-six".