1201621515400 has 96 divisors (see below), whose sum is σ = 2820708693000. Its totient is φ = 476018104320.

The previous prime is 1201621515373. The next prime is 1201621515449. The reversal of 1201621515400 is 45151261021.

It can be written as a sum of positive squares in 12 ways, for example, as 120782661444 + 1080838853956 = 347538^2 + 1039634^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51807006 + ... + 51830194.

Almost surely, 2^{1201621515400} is an apocalyptic number.

1201621515400 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 1201621515400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1410354346500).

1201621515400 is an abundant number, since it is smaller than the sum of its proper divisors (1619087177600).

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

1201621515400 is a wasteful number, since it uses less digits than its factorization.

1201621515400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25691 (or 25682 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 1201621515400 its reverse (45151261021), we get a palindrome (1246772776421).

The spelling of 1201621515400 in words is "one trillion, two hundred one billion, six hundred twenty-one million, five hundred fifteen thousand, four hundred".