1211531015604 has 192 divisors, whose sum is σ = 3664479522816. Its totient is φ = 302775238656.

The previous prime is 1211531015551. The next prime is 1211531015623. The reversal of 1211531015604 is 4065101351121.

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 63 ways as a sum of consecutive naturals, for example, 2462004 + ... + 2912820.

It is an arithmetic number, because the mean of its divisors is an integer number (19085830848).

Almost surely, 2^{1211531015604} is an apocalyptic number.

1211531015604 is a gapful number since it is divisible by the number (14) 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 1211531015604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1832239761408).

1211531015604 is an abundant number, since it is smaller than the sum of its proper divisors (2452948507212).

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

1211531015604 is a wasteful number, since it uses less digits than its factorization.

1211531015604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450974 (or 450972 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

Adding to 1211531015604 its reverse (4065101351121), we get a palindrome (5276632366725).

The spelling of 1211531015604 in words is "one trillion, two hundred eleven billion, five hundred thirty-one million, fifteen thousand, six hundred four".