19951611485521 has 16 divisors (see below), whose sum is σ = 20926485740160. Its totient is φ = 18995967849600.

The previous prime is 19951611485479. The next prime is 19951611485557. The reversal of 19951611485521 is 12558411615991.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 19951611485521 - 2⁹ = 19951611485009 is a prime.

It is a super-3 number, since 3×19951611485521³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19951611485021) 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, 9760036 + ... + 11625898.

It is an arithmetic number, because the mean of its divisors is an integer number (1307905358760).

Almost surely, 2^{19951611485521} is an apocalyptic number.

It is an amenable number.

19951611485521 is a deficient number, since it is larger than the sum of its proper divisors (974874254639).

19951611485521 is a wasteful number, since it uses less digits than its factorization.

19951611485521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1871016.

The product of its digits is 3888000, while the sum is 58.

The spelling of 19951611485521 in words is "nineteen trillion, nine hundred fifty-one billion, six hundred eleven million, four hundred eighty-five thousand, five hundred twenty-one".