21450551100 has 72 divisors (see below), whose sum is σ = 67705749888. Its totient is φ = 5200132800.

The previous prime is 21450551071. The next prime is 21450551131. The reversal of 21450551100 is 115505412.

It is a super-2 number, since 2×21450551100² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3246784 + ... + 3253383.

Almost surely, 2^21450551100 is an apocalyptic number.

21450551100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21450551100 is an abundant number, since it is smaller than the sum of its proper divisors (46255198788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21450551100 is a wasteful number, since it uses less digits than its factorization.

21450551100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6500195 (or 6500188 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 24.

The spelling of 21450551100 in words is "twenty-one billion, four hundred fifty million, five hundred fifty-one thousand, one hundred".