21154345 has 8 divisors (see below), whose sum is σ = 25554240. Its totient is φ = 16810800.

The previous prime is 21154339. The next prime is 21154381. The reversal of 21154345 is 54345112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21154345 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13255 + ... + 14764.

It is an arithmetic number, because the mean of its divisors is an integer number (3194280).

Almost surely, 2^21154345 is an apocalyptic number.

It is an amenable number.

21154345 is a deficient number, since it is larger than the sum of its proper divisors (4399895).

21154345 is a wasteful number, since it uses less digits than its factorization.

21154345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28175.

The product of its digits is 2400, while the sum is 25.

The square root of 21154345 is about 4599.3852850136. The cubic root of 21154345 is about 276.5666829567.

Adding to 21154345 its reverse (54345112), we get a palindrome (75499457).

The spelling of 21154345 in words is "twenty-one million, one hundred fifty-four thousand, three hundred forty-five".