21070425 has 12 divisors (see below), whose sum is σ = 34836560. Its totient is φ = 11237520.

The previous prime is 21070403. The next prime is 21070447. The reversal of 21070425 is 52407012.

It is an interprime number because it is at equal distance from previous prime (21070403) and next prime (21070447).

It is not a de Polignac number, because 21070425 - 2⁵ = 21070393 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140395 + ... + 140544.

Almost surely, 2^21070425 is an apocalyptic number.

21070425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21070425 is a deficient number, since it is larger than the sum of its proper divisors (13766135).

21070425 is a wasteful number, since it uses less digits than its factorization.

21070425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280952 (or 280947 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21070425 is about 4590.2532609868. The cubic root of 21070425 is about 276.2004818323.

Adding to 21070425 its reverse (52407012), we get a palindrome (73477437).

The spelling of 21070425 in words is "twenty-one million, seventy thousand, four hundred twenty-five".