21054715 has 8 divisors (see below), whose sum is σ = 27562608. Its totient is φ = 15312480.

The previous prime is 21054703. The next prime is 21054757. The reversal of 21054715 is 51745012.

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

It is not a de Polignac number, because 21054715 - 2¹⁹ = 20530427 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21054715.

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, 191352 + ... + 191461.

It is an arithmetic number, because the mean of its divisors is an integer number (3445326).

Almost surely, 2^21054715 is an apocalyptic number.

21054715 is a deficient number, since it is larger than the sum of its proper divisors (6507893).

21054715 is a wasteful number, since it uses less digits than its factorization.

21054715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382829.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21054715 is about 4588.5417073401. The cubic root of 21054715 is about 276.1318202142.

Adding to 21054715 its reverse (51745012), we get a palindrome (72799727).

The spelling of 21054715 in words is "twenty-one million, fifty-four thousand, seven hundred fifteen".