21374145 has 64 divisors (see below), whose sum is σ = 43142400. Its totient is φ = 9953280.

The previous prime is 21374113. The next prime is 21374147. The reversal of 21374145 is 54147312.

It is not a de Polignac number, because 21374145 - 2⁵ = 21374113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21374147) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33025 + ... + 33665.

It is an arithmetic number, because the mean of its divisors is an integer number (674100).

Almost surely, 2^21374145 is an apocalyptic number.

It is an amenable number.

21374145 is an abundant number, since it is smaller than the sum of its proper divisors (21768255).

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

21374145 is a wasteful number, since it uses less digits than its factorization.

21374145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687 (or 681 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21374145 is about 4623.2180350920. The cubic root of 21374145 is about 277.5212547635.

The spelling of 21374145 in words is "twenty-one million, three hundred seventy-four thousand, one hundred forty-five".