1647155251261 has 16 divisors (see below), whose sum is σ = 1851227763840. Its totient is φ = 1454152772160.

The previous prime is 1647155251249. The next prime is 1647155251271. The reversal of 1647155251261 is 1621525517461.

It is a cyclic number.

It is not a de Polignac number, because 1647155251261 - 2⁹ = 1647155250749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1647155251211) 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, 1933866 + ... + 2652196.

It is an arithmetic number, because the mean of its divisors is an integer number (115701735240).

Almost surely, 2^{1647155251261} is an apocalyptic number.

It is an amenable number.

1647155251261 is a deficient number, since it is larger than the sum of its proper divisors (204072512579).

1647155251261 is a wasteful number, since it uses less digits than its factorization.

1647155251261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726036.

The product of its digits is 504000, while the sum is 46.

The spelling of 1647155251261 in words is "one trillion, six hundred forty-seven billion, one hundred fifty-five million, two hundred fifty-one thousand, two hundred sixty-one".