21901818384340 has 24 divisors (see below), whose sum is σ = 45993907516032. Its totient is φ = 8760710418720.

The previous prime is 21901818384331. The next prime is 21901818384371. The reversal of 21901818384340 is 4348381810912.

It is a super-2 number, since 2×21901818384340² (a number of 27 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 7 ways as a sum of consecutive naturals, for example, 17385145 + ... + 18602335.

It is an arithmetic number, because the mean of its divisors is an integer number (1916412813168).

Almost surely, 2^{21901818384340} is an apocalyptic number.

21901818384340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21901818384340 is an abundant number, since it is smaller than the sum of its proper divisors (24092089131692).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21901818384340 is a wasteful number, since it uses less digits than its factorization.

21901818384340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116887 (or 2116885 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 52.

The spelling of 21901818384340 in words is "twenty-one trillion, nine hundred one billion, eight hundred eighteen million, three hundred eighty-four thousand, three hundred forty".