2181921656254 has 8 divisors (see below), whose sum is σ = 3272959789488. Its totient is φ = 1090935059760.

The previous prime is 2181921656227. The next prime is 2181921656279. The reversal of 2181921656254 is 4526561291812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×2181921656254² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12778167 + ... + 12947794.

It is an arithmetic number, because the mean of its divisors is an integer number (409119973686).

Almost surely, 2^{2181921656254} is an apocalyptic number.

2181921656254 is a deficient number, since it is larger than the sum of its proper divisors (1091038133234).

2181921656254 is a wasteful number, since it uses less digits than its factorization.

2181921656254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25768370.

The product of its digits is 2073600, while the sum is 52.

The spelling of 2181921656254 in words is "two trillion, one hundred eighty-one billion, nine hundred twenty-one million, six hundred fifty-six thousand, two hundred fifty-four".