21540214101 has 32 divisors (see below), whose sum is σ = 34617369600. Its totient is φ = 11638373760.

The previous prime is 21540214093. The next prime is 21540214103. The reversal of 21540214101 is 10141204512.

It is not a de Polignac number, because 21540214101 - 2³ = 21540214093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540214103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 156070 + ... + 259688.

It is an arithmetic number, because the mean of its divisors is an integer number (1081792800).

Almost surely, 2^21540214101 is an apocalyptic number.

21540214101 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21540214101 is a deficient number, since it is larger than the sum of its proper divisors (13077155499).

21540214101 is a wasteful number, since it uses less digits than its factorization.

21540214101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104169.

The product of its (nonzero) digits is 320, while the sum is 21.

Adding to 21540214101 its reverse (10141204512), we get a palindrome (31681418613).

It can be divided in two parts, 215402 and 14101, that added together give a triangular number (229503 = T₆₇₇).

The spelling of 21540214101 in words is "twenty-one billion, five hundred forty million, two hundred fourteen thousand, one hundred one".