21751480 has 16 divisors (see below), whose sum is σ = 48940920. Its totient is φ = 8700576.

The previous prime is 21751469. The next prime is 21751481. The reversal of 21751480 is 8415712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21751481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271854 + ... + 271933.

Almost surely, 2^21751480 is an apocalyptic number.

21751480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21751480 is an abundant number, since it is smaller than the sum of its proper divisors (27189440).

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

21751480 is a wasteful number, since it uses less digits than its factorization.

21751480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543798 (or 543794 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21751480 is about 4663.8481965004. The cubic root of 21751480 is about 279.1448398568.

It can be divided in two parts, 2175 and 1480, that added together give a triangular number (3655 = T₈₅).

The spelling of 21751480 in words is "twenty-one million, seven hundred fifty-one thousand, four hundred eighty".