1213136640 has 432 divisors, whose sum is σ = 4489605120. Its totient is φ = 301916160.

The previous prime is 1213136623. The next prime is 1213136651. The reversal of 1213136640 is 466313121.

1213136640 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 13 + 6 + 640 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15356121 + ... + 15356199.

Almost surely, 2^1213136640 is an apocalyptic number.

1213136640 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 1213136640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2244802560).

1213136640 is an abundant number, since it is smaller than the sum of its proper divisors (3276468480).

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

1213136640 is a wasteful number, since it uses less digits than its factorization.

1213136640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 1213136640 is about 34830.1111109339. Note that the first 5 decimals coincide. The cubic root of 1213136640 is about 1066.5222165503.

Adding to 1213136640 its reverse (466313121), we get a palindrome (1679449761).

The spelling of 1213136640 in words is "one billion, two hundred thirteen million, one hundred thirty-six thousand, six hundred forty".