20011220154 has 64 divisors (see below), whose sum is σ = 45258393600. Its totient is φ = 6552961776.

The previous prime is 20011220153. The next prime is 20011220167. The reversal of 20011220154 is 45102211002.

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 (20011220153) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 789807 + ... + 814749.

It is an arithmetic number, because the mean of its divisors is an integer number (707162400).

Almost surely, 2^20011220154 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20011220154, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22629196800).

20011220154 is an abundant number, since it is smaller than the sum of its proper divisors (25247173446).

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

20011220154 is a wasteful number, since it uses less digits than its factorization.

20011220154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25216 (or 25210 counting only the distinct ones).

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

Adding to 20011220154 its reverse (45102211002), we get a palindrome (65113431156).

The spelling of 20011220154 in words is "twenty billion, eleven million, two hundred twenty thousand, one hundred fifty-four".