21425146 has 16 divisors (see below), whose sum is σ = 33132960. Its totient is φ = 10383120.

The previous prime is 21425099. The next prime is 21425147. The reversal of 21425146 is 64152412.

It is a happy number.

It is a super-2 number, since 2×21425146² = 918073762242632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21425146.

It is not an unprimeable number, because it can be changed into a prime (21425147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30661 + ... + 31351.

It is an arithmetic number, because the mean of its divisors is an integer number (2070810).

Almost surely, 2^21425146 is an apocalyptic number.

21425146 is a deficient number, since it is larger than the sum of its proper divisors (11707814).

21425146 is a wasteful number, since it uses less digits than its factorization.

21425146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149.

The product of its digits is 1920, while the sum is 25.

The square root of 21425146 is about 4628.7304955031. The cubic root of 21425146 is about 277.7418112485.

Adding to 21425146 its reverse (64152412), we get a palindrome (85577558).

The spelling of 21425146 in words is "twenty-one million, four hundred twenty-five thousand, one hundred forty-six".