1291997952 has 504 divisors, whose sum is σ = 4718402304. Its totient is φ = 344881152.

The previous prime is 1291997951. The next prime is 1291997981. The reversal of 1291997952 is 2597991921.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291997951) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 30046443 + ... + 30046485.

Almost surely, 2^1291997952 is an apocalyptic number.

1291997952 is a gapful number since it is divisible by the number (12) 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 1291997952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2359201152).

1291997952 is an abundant number, since it is smaller than the sum of its proper divisors (3426404352).

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

1291997952 is an frugal number, since it uses more digits than its factorization.

1291997952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 78 counting only the distinct ones).

The product of its digits is 918540, while the sum is 54.

The square root of 1291997952 is about 35944.3730227695. The cubic root of 1291997952 is about 1089.1489448622.

The spelling of 1291997952 in words is "one billion, two hundred ninety-one million, nine hundred ninety-seven thousand, nine hundred fifty-two".