1216751540 has 24 divisors (see below), whose sum is σ = 2705483592. Its totient is φ = 458071040.

The previous prime is 1216751527. The next prime is 1216751563. The reversal of 1216751540 is 451576121.

It can be written as a sum of positive squares in 4 ways, for example, as 240064036 + 976687504 = 15494^2 + 31252^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1216751497 and 1216751506.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1789001 + ... + 1789680.

It is an arithmetic number, because the mean of its divisors is an integer number (112728483).

Almost surely, 2^1216751540 is an apocalyptic number.

1216751540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216751540 is an abundant number, since it is smaller than the sum of its proper divisors (1488732052).

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

1216751540 is a wasteful number, since it uses less digits than its factorization.

1216751540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3578707 (or 3578705 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 1216751540 is about 34881.9658276308. The cubic root of 1216751540 is about 1067.5805057140.

The spelling of 1216751540 in words is "one billion, two hundred sixteen million, seven hundred fifty-one thousand, five hundred forty".