2391761988 has 108 divisors (see below), whose sum is σ = 7594874560. Its totient is φ = 621228960.

The previous prime is 2391761959. The next prime is 2391761989. The reversal of 2391761988 is 8891671932.

2391761988 is a `hidden beast` number, since 2 + 3 + 9 + 17 + 619 + 8 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (2391761989) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8728 + ... + 69711.

Almost surely, 2^2391761988 is an apocalyptic number.

2391761988 is a gapful number since it is divisible by the number (28) 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 2391761988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3797437280).

2391761988 is an abundant number, since it is smaller than the sum of its proper divisors (5203112572).

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

2391761988 is a wasteful number, since it uses less digits than its factorization.

2391761988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78478 (or 78462 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 2391761988 is about 48905.6437233986. The cubic root of 2391761988 is about 1337.3322561110.

It can be divided in two parts, 23917 and 61988, that added together give a triangular number (85905 = T₄₁₄).

The spelling of 2391761988 in words is "two billion, three hundred ninety-one million, seven hundred sixty-one thousand, nine hundred eighty-eight".