21401145 has 16 divisors (see below), whose sum is σ = 38046720. Its totient is φ = 11413872.

The previous prime is 21401137. The next prime is 21401203. The reversal of 21401145 is 54110412.

It is not a de Polignac number, because 21401145 - 2³ = 21401137 is a prime.

It is a super-2 number, since 2×21401145² = 916018014622050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79129 + ... + 79398.

It is an arithmetic number, because the mean of its divisors is an integer number (2377920).

Almost surely, 2^21401145 is an apocalyptic number.

It is an amenable number.

21401145 is a deficient number, since it is larger than the sum of its proper divisors (16645575).

21401145 is a wasteful number, since it uses less digits than its factorization.

21401145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158541 (or 158535 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21401145 is about 4626.1371574998. The cubic root of 21401145 is about 277.6380613225.

Adding to 21401145 its reverse (54110412), we get a palindrome (75511557).

The spelling of 21401145 in words is "twenty-one million, four hundred one thousand, one hundred forty-five".