21542140455 has 32 divisors (see below), whose sum is σ = 37682523648. Its totient is φ = 10421980800.

The previous prime is 21542140453. The next prime is 21542140471. The reversal of 21542140455 is 55404124512.

It is a happy number.

It is not a de Polignac number, because 21542140455 - 2¹ = 21542140453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21542140453) 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, 65539 + ... + 217668.

It is an arithmetic number, because the mean of its divisors is an integer number (1177578864).

Almost surely, 2^21542140455 is an apocalyptic number.

21542140455 is a deficient number, since it is larger than the sum of its proper divisors (16140383193).

21542140455 is a wasteful number, since it uses less digits than its factorization.

21542140455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283687.

The product of its (nonzero) digits is 32000, while the sum is 33.

Adding to 21542140455 its reverse (55404124512), we get a palindrome (76946264967).

The spelling of 21542140455 in words is "twenty-one billion, five hundred forty-two million, one hundred forty thousand, four hundred fifty-five".