1261905429654 has 12 divisors (see below), whose sum is σ = 2734128430956. Its totient is φ = 420635143212.

The previous prime is 1261905429641. The next prime is 1261905429671. The reversal of 1261905429654 is 4569245091621.

It is a happy number.

1261905429654 is a `hidden beast` number, since 1 + 2 + 6 + 1 + 9 + 0 + 542 + 96 + 5 + 4 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261905429654.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35052928584 + ... + 35052928619.

It is an arithmetic number, because the mean of its divisors is an integer number (227844035913).

Almost surely, 2^{1261905429654} is an apocalyptic number.

1261905429654 is an abundant number, since it is smaller than the sum of its proper divisors (1472223001302).

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

1261905429654 is a wasteful number, since it uses less digits than its factorization.

1261905429654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70105857211 (or 70105857208 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 54.

The spelling of 1261905429654 in words is "one trillion, two hundred sixty-one billion, nine hundred five million, four hundred twenty-nine thousand, six hundred fifty-four".