1211025042591 has 16 divisors (see below), whose sum is σ = 1987323147264. Its totient is φ = 638782439904.

The previous prime is 1211025042551. The next prime is 1211025042599. The reversal of 1211025042591 is 1952405201121.

It is not a de Polignac number, because 1211025042591 - 2¹¹ = 1211025040543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211025042599) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2217994311 + ... + 2217994856.

It is an arithmetic number, because the mean of its divisors is an integer number (124207696704).

Almost surely, 2^{1211025042591} is an apocalyptic number.

1211025042591 is a deficient number, since it is larger than the sum of its proper divisors (776298104673).

1211025042591 is a wasteful number, since it uses less digits than its factorization.

1211025042591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4435989190.

The product of its (nonzero) digits is 7200, while the sum is 33.

The spelling of 1211025042591 in words is "one trillion, two hundred eleven billion, twenty-five million, forty-two thousand, five hundred ninety-one".