21151545 has 8 divisors (see below), whose sum is σ = 33842496. Its totient is φ = 11280816.

The previous prime is 21151489. The next prime is 21151561. The reversal of 21151545 is 54515112.

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

It is not a de Polignac number, because 21151545 - 2¹⁴ = 21135161 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, 705037 + ... + 705066.

It is an arithmetic number, because the mean of its divisors is an integer number (4230312).

Almost surely, 2^21151545 is an apocalyptic number.

It is an amenable number.

21151545 is a deficient number, since it is larger than the sum of its proper divisors (12690951).

21151545 is a wasteful number, since it uses less digits than its factorization.

21151545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1410111.

The product of its digits is 1000, while the sum is 24.

The square root of 21151545 is about 4599.0808864381. The cubic root of 21151545 is about 276.5544802488.

Adding to 21151545 its reverse (54515112), we get a palindrome (75666657).

The spelling of 21151545 in words is "twenty-one million, one hundred fifty-one thousand, five hundred forty-five".