21072675 has 24 divisors (see below), whose sum is σ = 37521904. Its totient is φ = 10373760.

The previous prime is 21072671. The next prime is 21072677. The reversal of 21072675 is 57627012.

It is not a de Polignac number, because 21072675 - 2² = 21072671 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21072671) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9832 + ... + 11781.

Almost surely, 2^21072675 is an apocalyptic number.

21072675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21072675 is a deficient number, since it is larger than the sum of its proper divisors (16449229).

21072675 is a wasteful number, since it uses less digits than its factorization.

21072675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21639 (or 21634 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21072675 is about 4590.4983389606. The cubic root of 21072675 is about 276.2103128152.

Adding to 21072675 its reverse (57627012), we get a palindrome (78699687).

The spelling of 21072675 in words is "twenty-one million, seventy-two thousand, six hundred seventy-five".