21145146 has 32 divisors (see below), whose sum is σ = 46305216. Its totient is φ = 6384000.

The previous prime is 21145141. The next prime is 21145169. The reversal of 21145146 is 64154112.

It is a happy number.

It is a super-2 number, since 2×21145146² = 894234398722632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21145141) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 27406 + ... + 28166.

It is an arithmetic number, because the mean of its divisors is an integer number (1447038).

Almost surely, 2^21145146 is an apocalyptic number.

21145146 is an abundant number, since it is smaller than the sum of its proper divisors (25160070).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21145146 is a wasteful number, since it uses less digits than its factorization.

21145146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198.

The product of its digits is 960, while the sum is 24.

The square root of 21145146 is about 4598.3851513330. The cubic root of 21145146 is about 276.5265886596.

Adding to 21145146 its reverse (64154112), we get a palindrome (85299258).

It can be divided in two parts, 2114 and 5146, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 21145146 in words is "twenty-one million, one hundred forty-five thousand, one hundred forty-six".