1261990044036 has 36 divisors (see below), whose sum is σ = 3276247430092. Its totient is φ = 409294067904.

The previous prime is 1261990044019. The next prime is 1261990044127. The reversal of 1261990044036 is 6304400991621.

1261990044036 is a `hidden beast` number, since 12 + 6 + 199 + 0 + 0 + 440 + 3 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 753521219136 + 508468824900 = 868056^2 + 713070^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 1261990043982 and 1261990044000.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 473718655 + ... + 473721318.

Almost surely, 2^{1261990044036} is an apocalyptic number.

It is an amenable number.

1261990044036 is an abundant number, since it is smaller than the sum of its proper divisors (2014257386056).

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

1261990044036 is a wasteful number, since it uses less digits than its factorization.

1261990044036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947440020 (or 947440015 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The spelling of 1261990044036 in words is "one trillion, two hundred sixty-one billion, nine hundred ninety million, forty-four thousand, thirty-six".