21015154 has 8 divisors (see below), whose sum is σ = 31609728. Its totient is φ = 10478580.

The previous prime is 21015143. The next prime is 21015161. The reversal of 21015154 is 45151012.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13582 + ... + 15049.

It is an arithmetic number, because the mean of its divisors is an integer number (3951216).

Almost surely, 2^21015154 is an apocalyptic number.

21015154 is a deficient number, since it is larger than the sum of its proper divisors (10594574).

21015154 is a wasteful number, since it uses less digits than its factorization.

21015154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29000.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 21015154 is about 4584.2288337298. The cubic root of 21015154 is about 275.9587647561.

Adding to 21015154 its reverse (45151012), we get a palindrome (66166166).

The spelling of 21015154 in words is "twenty-one million, fifteen thousand, one hundred fifty-four".