21540777626537 has 16 divisors (see below), whose sum is σ = 23517844441728. Its totient is φ = 19609490517120.

The previous prime is 21540777626531. The next prime is 21540777626551. The reversal of 21540777626537 is 73562677704512.

It is a cyclic number.

It is not a de Polignac number, because 21540777626537 - 2¹⁰ = 21540777625513 is a prime.

It is a super-2 number, since 2×21540777626537² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21540777626537.

It is not an unprimeable number, because it can be changed into a prime (21540777626531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8612612 + ... + 10828602.

It is an arithmetic number, because the mean of its divisors is an integer number (1469865277608).

Almost surely, 2^{21540777626537} is an apocalyptic number.

It is an amenable number.

21540777626537 is a deficient number, since it is larger than the sum of its proper divisors (1977066815191).

21540777626537 is a wasteful number, since it uses less digits than its factorization.

21540777626537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2226320.

The product of its (nonzero) digits is 103723200, while the sum is 62.

The spelling of 21540777626537 in words is "twenty-one trillion, five hundred forty billion, seven hundred seventy-seven million, six hundred twenty-six thousand, five hundred thirty-seven".