1261211134040 has 64 divisors (see below), whose sum is σ = 3333830844960. Its totient is φ = 423343595520.

The previous prime is 1261211133997. The next prime is 1261211134067. The reversal of 1261211134040 is 404311121621.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110240009 + ... + 110251448.

Almost surely, 2^{1261211134040} is an apocalyptic number.

1261211134040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261211134040 is an abundant number, since it is smaller than the sum of its proper divisors (2072619710920).

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

1261211134040 is a wasteful number, since it uses less digits than its factorization.

1261211134040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220491492 (or 220491488 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

Adding to 1261211134040 its reverse (404311121621), we get a palindrome (1665522255661).

The spelling of 1261211134040 in words is "one trillion, two hundred sixty-one billion, two hundred eleven million, one hundred thirty-four thousand, forty".