1261406136220 has 24 divisors (see below), whose sum is σ = 2668288314384. Its totient is φ = 500879515776.

The previous prime is 1261406136209. The next prime is 1261406136223. The reversal of 1261406136220 is 226316041621.

It is a super-2 number, since 2×1261406136220² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261406136223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230180862 + ... + 230186341.

It is an arithmetic number, because the mean of its divisors is an integer number (111178679766).

Almost surely, 2^{1261406136220} is an apocalyptic number.

1261406136220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261406136220 is an abundant number, since it is smaller than the sum of its proper divisors (1406882178164).

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

1261406136220 is a wasteful number, since it uses less digits than its factorization.

1261406136220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460367349 (or 460367347 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The spelling of 1261406136220 in words is "one trillion, two hundred sixty-one billion, four hundred six million, one hundred thirty-six thousand, two hundred twenty".