121166666621 has 32 divisors (see below), whose sum is σ = 164362614528. Its totient is φ = 86254295040.

The previous prime is 121166666611. The next prime is 121166666627. The reversal of 121166666621 is 126666661121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121166666621 is a prime.

It is a super-2 number, since 2×121166666621² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121166666627) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 526850 + ... + 721043.

It is an arithmetic number, because the mean of its divisors is an integer number (5136331704).

Almost surely, 2^121166666621 is an apocalyptic number.

121166666621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121166666621 is a deficient number, since it is larger than the sum of its proper divisors (43195947907).

121166666621 is a wasteful number, since it uses less digits than its factorization.

121166666621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248021.

The product of its digits is 186624, while the sum is 44.

It can be divided in two parts, 121166 and 666621, that added together give a palindrome (787787).

The spelling of 121166666621 in words is "one hundred twenty-one billion, one hundred sixty-six million, six hundred sixty-six thousand, six hundred twenty-one".