21354544635240 has 32 divisors (see below), whose sum is σ = 64063633906080. Its totient is φ = 5694545236032.

The previous prime is 21354544635233. The next prime is 21354544635241. The reversal of 21354544635240 is 4253644545312.

It is a self number, because there is not a number n which added to its sum of digits gives 21354544635240.

It is not an unprimeable number, because it can be changed into a prime (21354544635241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88977269194 + ... + 88977269433.

It is an arithmetic number, because the mean of its divisors is an integer number (2001988559565).

Almost surely, 2^{21354544635240} is an apocalyptic number.

21354544635240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21354544635240 is an abundant number, since it is smaller than the sum of its proper divisors (42709089270840).

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

21354544635240 is a wasteful number, since it uses less digits than its factorization.

21354544635240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177954538641 (or 177954538637 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 48.

The spelling of 21354544635240 in words is "twenty-one trillion, three hundred fifty-four billion, five hundred forty-four million, six hundred thirty-five thousand, two hundred forty".