21540455346 has 16 divisors (see below), whose sum is σ = 44082792864. Its totient is φ = 7013171424.

The previous prime is 21540455341. The next prime is 21540455347. The reversal of 21540455346 is 64355404512.

It is not an unprimeable number, because it can be changed into a prime (21540455341) 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, 41744811 + ... + 41745326.

It is an arithmetic number, because the mean of its divisors is an integer number (2755174554).

Almost surely, 2^21540455346 is an apocalyptic number.

21540455346 is an abundant number, since it is smaller than the sum of its proper divisors (22542337518).

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

21540455346 is a wasteful number, since it uses less digits than its factorization.

21540455346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83490185.

The product of its (nonzero) digits is 288000, while the sum is 39.

Adding to 21540455346 its reverse (64355404512), we get a palindrome (85895859858).

The spelling of 21540455346 in words is "twenty-one billion, five hundred forty million, four hundred fifty-five thousand, three hundred forty-six".