21001154 has 8 divisors (see below), whose sum is σ = 33354828. Its totient is φ = 9882880.

The previous prime is 21001153. The next prime is 21001177. The reversal of 21001154 is 45110012.

It can be written as a sum of positive squares in 2 ways, for example, as 16687225 + 4313929 = 4085^2 + 2077^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21001153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 308807 + ... + 308874.

Almost surely, 2^21001154 is an apocalyptic number.

21001154 is a deficient number, since it is larger than the sum of its proper divisors (12353674).

21001154 is a wasteful number, since it uses less digits than its factorization.

21001154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617700.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21001154 is about 4582.7016049488. The cubic root of 21001154 is about 275.8974711940.

Adding to 21001154 its reverse (45110012), we get a palindrome (66111166).

The spelling of 21001154 in words is "twenty-one million, one thousand, one hundred fifty-four".