21551965454 has 16 divisors (see below), whose sum is σ = 33409514880. Its totient is φ = 10420112640.

The previous prime is 21551965453. The next prime is 21551965489. The reversal of 21551965454 is 45456915512.

It is a super-2 number, since 2×21551965454² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21551965399 and 21551965408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551965453) 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, 1153694 + ... + 1172225.

It is an arithmetic number, because the mean of its divisors is an integer number (2088094680).

Almost surely, 2^21551965454 is an apocalyptic number.

21551965454 is a deficient number, since it is larger than the sum of its proper divisors (11857549426).

21551965454 is a wasteful number, since it uses less digits than its factorization.

21551965454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2326075.

The product of its digits is 1080000, while the sum is 47.

The spelling of 21551965454 in words is "twenty-one billion, five hundred fifty-one million, nine hundred sixty-five thousand, four hundred fifty-four".