21201002154 has 32 divisors (see below), whose sum is σ = 47123484480. Its totient is φ = 7065478800.

The previous prime is 21201002111. The next prime is 21201002159. The reversal of 21201002154 is 45120010212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21201002159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 226464 + ... + 306084.

It is an arithmetic number, because the mean of its divisors is an integer number (1472608890).

Almost surely, 2^21201002154 is an apocalyptic number.

21201002154 is an abundant number, since it is smaller than the sum of its proper divisors (25922482326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21201002154 is a wasteful number, since it uses less digits than its factorization.

21201002154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84563 (or 84557 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 21201002154 its reverse (45120010212), we get a palindrome (66321012366).

The spelling of 21201002154 in words is "twenty-one billion, two hundred one million, two thousand, one hundred fifty-four".