21072154 has 8 divisors (see below), whose sum is σ = 32698260. Its totient is φ = 10172736.

The previous prime is 21072137. The next prime is 21072169. The reversal of 21072154 is 45127012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20025625 + 1046529 = 4475^2 + 1023^2 .

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, 181599 + ... + 181714.

Almost surely, 2^21072154 is an apocalyptic number.

21072154 is a deficient number, since it is larger than the sum of its proper divisors (11626106).

21072154 is a wasteful number, since it uses less digits than its factorization.

21072154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363344.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21072154 is about 4590.4415909583. The cubic root of 21072154 is about 276.2080364587.

Adding to 21072154 its reverse (45127012), we get a palindrome (66199166).

The spelling of 21072154 in words is "twenty-one million, seventy-two thousand, one hundred fifty-four".