21754450780 has 48 divisors (see below), whose sum is σ = 47200817664. Its totient is φ = 8416860480.

The previous prime is 21754450763. The next prime is 21754450813. The reversal of 21754450780 is 8705445712.

It is a super-2 number, since 2×21754450780² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34216 + ... + 211375.

It is an arithmetic number, because the mean of its divisors is an integer number (983350368).

Almost surely, 2^21754450780 is an apocalyptic number.

21754450780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21754450780 is an abundant number, since it is smaller than the sum of its proper divisors (25446366884).

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

21754450780 is a wasteful number, since it uses less digits than its factorization.

21754450780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245746 (or 245744 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 43.

It can be divided in two parts, 217544 and 50780, that added together give a square (268324 = 518²).

The spelling of 21754450780 in words is "twenty-one billion, seven hundred fifty-four million, four hundred fifty thousand, seven hundred eighty".