21533350154 has 4 divisors (see below), whose sum is σ = 32300025234. Its totient is φ = 10766675076.

The previous prime is 21533350151. The next prime is 21533350177. The reversal of 21533350154 is 45105333512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15073209529 + 6460140625 = 122773^2 + 80375^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21533350154.

It is not an unprimeable number, because it can be changed into a prime (21533350151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5383337537 + ... + 5383337540.

Almost surely, 2^21533350154 is an apocalyptic number.

21533350154 is a deficient number, since it is larger than the sum of its proper divisors (10766675080).

21533350154 is a wasteful number, since it uses less digits than its factorization.

21533350154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10766675079.

The product of its (nonzero) digits is 27000, while the sum is 32.

Adding to 21533350154 its reverse (45105333512), we get a palindrome (66638683666).

The spelling of 21533350154 in words is "twenty-one billion, five hundred thirty-three million, three hundred fifty thousand, one hundred fifty-four".