21046772 has 6 divisors (see below), whose sum is σ = 36831858. Its totient is φ = 10523384.

The previous prime is 21046757. The next prime is 21046783. The reversal of 21046772 is 27764012.

It can be written as a sum of positive squares in only one way, i.e., 21031396 + 15376 = 4586^2 + 124^2 .

It is a super-2 number, since 2×21046772² = 885933223239968, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2630843 + ... + 2630850.

It is an arithmetic number, because the mean of its divisors is an integer number (6138643).

Almost surely, 2^21046772 is an apocalyptic number.

It is an amenable number.

21046772 is a deficient number, since it is larger than the sum of its proper divisors (15785086).

21046772 is a wasteful number, since it uses less digits than its factorization.

21046772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5261697 (or 5261695 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 21046772 is about 4587.6761001623. The cubic root of 21046772 is about 276.0970917948.

The spelling of 21046772 in words is "twenty-one million, forty-six thousand, seven hundred seventy-two".