1261285155651 has 16 divisors (see below), whose sum is σ = 1684506218400. Its totient is φ = 839461113600.

The previous prime is 1261285155649. The next prime is 1261285155673. The reversal of 1261285155651 is 1565515821621.

It is not a de Polignac number, because 1261285155651 - 2¹ = 1261285155649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1261285155651.

It is not an unprimeable number, because it can be changed into a prime (1261285155631) 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, 7501201 + ... + 7667501.

It is an arithmetic number, because the mean of its divisors is an integer number (105281638650).

Almost surely, 2^{1261285155651} is an apocalyptic number.

1261285155651 is a deficient number, since it is larger than the sum of its proper divisors (423221062749).

1261285155651 is a wasteful number, since it uses less digits than its factorization.

1261285155651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170486.

The product of its digits is 720000, while the sum is 48.

The spelling of 1261285155651 in words is "one trillion, two hundred sixty-one billion, two hundred eighty-five million, one hundred fifty-five thousand, six hundred fifty-one".