2191542957 has 12 divisors (see below), whose sum is σ = 3166058844. Its totient is φ = 1460799360.

The previous prime is 2191542937. The next prime is 2191542989. The reversal of 2191542957 is 7592451912.

2191542957 is a `hidden beast` number, since 2 + 19 + 1 + 542 + 95 + 7 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 709369956 + 1482173001 = 26634^2 + 38499^2 .

It is not a de Polignac number, because 2191542957 - 2¹¹ = 2191540909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191542937) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57663 + ... + 87795.

It is an arithmetic number, because the mean of its divisors is an integer number (263838237).

Almost surely, 2^2191542957 is an apocalyptic number.

It is an amenable number.

2191542957 is a deficient number, since it is larger than the sum of its proper divisors (974515887).

2191542957 is a wasteful number, since it uses less digits than its factorization.

2191542957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38220 (or 38217 counting only the distinct ones).

The product of its digits is 226800, while the sum is 45.

The square root of 2191542957 is about 46813.9184110880. The cubic root of 2191542957 is about 1298.9227677664.

It can be divided in two parts, 219154 and 2957, that added together give a triangular number (222111 = T₆₆₆).

The spelling of 2191542957 in words is "two billion, one hundred ninety-one million, five hundred forty-two thousand, nine hundred fifty-seven".