20404121550 has 24 divisors (see below), whose sum is σ = 50602221816. Its totient is φ = 5441099040.

The previous prime is 20404121519. The next prime is 20404121581. The reversal of 20404121550 is 5512140402.

It is an interprime number because it is at equal distance from previous prime (20404121519) and next prime (20404121581).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20404121550.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68013589 + ... + 68013888.

It is an arithmetic number, because the mean of its divisors is an integer number (2108425909).

Almost surely, 2^20404121550 is an apocalyptic number.

20404121550 is an abundant number, since it is smaller than the sum of its proper divisors (30198100266).

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

20404121550 is a wasteful number, since it uses less digits than its factorization.

20404121550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136027492 (or 136027487 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 20404121550 its reverse (5512140402), we get a palindrome (25916261952).

The spelling of 20404121550 in words is "twenty billion, four hundred four million, one hundred twenty-one thousand, five hundred fifty".