21029672 has 8 divisors (see below), whose sum is σ = 39430650. Its totient is φ = 10514832.

The previous prime is 21029647. The next prime is 21029677. The reversal of 21029672 is 27692012.

It can be written as a sum of positive squares in only one way, i.e., 16924996 + 4104676 = 4114^2 + 2026^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21029677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1314347 + ... + 1314362.

Almost surely, 2^21029672 is an apocalyptic number.

It is an amenable number.

21029672 is a deficient number, since it is larger than the sum of its proper divisors (18400978).

21029672 is a wasteful number, since it uses less digits than its factorization.

21029672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628715 (or 2628711 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 21029672 is about 4585.8120327811. The cubic root of 21029672 is about 276.0222974354.

The spelling of 21029672 in words is "twenty-one million, twenty-nine thousand, six hundred seventy-two".