21941810 has 32 divisors (see below), whose sum is σ = 43403904. Its totient is φ = 7920000.

The previous prime is 21941807. The next prime is 21941813. The reversal of 21941810 is 1814912.

It is an interprime number because it is at equal distance from previous prime (21941807) and next prime (21941813).

It is a super-2 number, since 2×21941810² = 962886052152200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21941810.

It is not an unprimeable number, because it can be changed into a prime (21941813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15950 + ... + 17270.

It is an arithmetic number, because the mean of its divisors is an integer number (1356372).

Almost surely, 2^21941810 is an apocalyptic number.

21941810 is a deficient number, since it is larger than the sum of its proper divisors (21462094).

21941810 is a wasteful number, since it uses less digits than its factorization.

21941810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 21941810 is about 4684.2085777642. The cubic root of 21941810 is about 279.9566684646.

It can be divided in two parts, 2194 and 1810, that added together give a palindrome (4004).

The spelling of 21941810 in words is "twenty-one million, nine hundred forty-one thousand, eight hundred ten".