1213687764 has 72 divisors (see below), whose sum is σ = 3159007488. Its totient is φ = 392610240.

The previous prime is 1213687753. The next prime is 1213687799. The reversal of 1213687764 is 4677863121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 647749 + ... + 649619.

It is an arithmetic number, because the mean of its divisors is an integer number (43875104).

Almost surely, 2^1213687764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213687764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1579503744).

1213687764 is an abundant number, since it is smaller than the sum of its proper divisors (1945319724).

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

1213687764 is a wasteful number, since it uses less digits than its factorization.

1213687764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2405 (or 2400 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 1213687764 is about 34838.0218152524. The cubic root of 1213687764 is about 1066.6836979485.

The spelling of 1213687764 in words is "one billion, two hundred thirteen million, six hundred eighty-seven thousand, seven hundred sixty-four".