21801416 has 32 divisors (see below), whose sum is σ = 50312640. Its totient is φ = 8624448.

The previous prime is 21801407. The next prime is 21801419. The reversal of 21801416 is 61410812.

It is a junction number, because it is equal to n+sod(n) for n = 21801391 and 21801400.

It is not an unprimeable number, because it can be changed into a prime (21801419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14246 + ... + 15701.

It is an arithmetic number, because the mean of its divisors is an integer number (1572270).

Almost surely, 2^21801416 is an apocalyptic number.

21801416 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21801416 is an abundant number, since it is smaller than the sum of its proper divisors (28511224).

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

21801416 is a wasteful number, since it uses less digits than its factorization.

21801416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29973 (or 29969 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 21801416 is about 4669.1986464489. The cubic root of 21801416 is about 279.3582923543.

The spelling of 21801416 in words is "twenty-one million, eight hundred one thousand, four hundred sixteen".