21550540351 has 16 divisors (see below), whose sum is σ = 22916044800. Its totient is φ = 20233452960.

The previous prime is 21550540337. The next prime is 21550540393. The reversal of 21550540351 is 15304505512.

It is a cyclic number.

It is not a de Polignac number, because 21550540351 - 2²¹ = 21548443199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550540651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144366 + ... + 252868.

It is an arithmetic number, because the mean of its divisors is an integer number (1432252800).

Almost surely, 2^21550540351 is an apocalyptic number.

21550540351 is a deficient number, since it is larger than the sum of its proper divisors (1365504449).

21550540351 is a wasteful number, since it uses less digits than its factorization.

21550540351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108726.

The product of its (nonzero) digits is 15000, while the sum is 31.

The spelling of 21550540351 in words is "twenty-one billion, five hundred fifty million, five hundred forty thousand, three hundred fifty-one".