1291522464 has 72 divisors (see below), whose sum is σ = 3697539300. Its totient is φ = 427603968.

The previous prime is 1291522457. The next prime is 1291522471. The reversal of 1291522464 is 4642251921.

It is a happy number.

1291522464 is a `hidden beast` number, since 1 + 2 + 91 + 522 + 46 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (1291522457) and next prime (1291522471).

It can be written as a sum of positive squares in 2 ways, for example, as 929762064 + 361760400 = 30492^2 + 19020^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27864 + ... + 57960.

Almost surely, 2^1291522464 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 1291522464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1848769650).

1291522464 is an abundant number, since it is smaller than the sum of its proper divisors (2406016836).

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

1291522464 is a wasteful number, since it uses less digits than its factorization.

1291522464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30262 (or 30251 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1291522464 is about 35937.7581938551. The cubic root of 1291522464 is about 1089.0153169937.

The spelling of 1291522464 in words is "one billion, two hundred ninety-one million, five hundred twenty-two thousand, four hundred sixty-four".