1551523321420 has 96 divisors (see below), whose sum is σ = 3449271329280. Its totient is φ = 584590970880.

The previous prime is 1551523321391. The next prime is 1551523321429. The reversal of 1551523321420 is 241233251551.

It is not an unprimeable number, because it can be changed into a prime (1551523321429) 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, 177698455 + ... + 177707185.

It is an arithmetic number, because the mean of its divisors is an integer number (35929909680).

Almost surely, 2^{1551523321420} is an apocalyptic number.

1551523321420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1551523321420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1724635664640).

1551523321420 is an abundant number, since it is smaller than the sum of its proper divisors (1897748007860).

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

1551523321420 is a wasteful number, since it uses less digits than its factorization.

1551523321420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11375 (or 11373 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 34.

Adding to 1551523321420 its reverse (241233251551), we get a palindrome (1792756572971).

The spelling of 1551523321420 in words is "one trillion, five hundred fifty-one billion, five hundred twenty-three million, three hundred twenty-one thousand, four hundred twenty".