21961610 has 32 divisors (see below), whose sum is σ = 43949952. Its totient is φ = 7833280.

The previous prime is 21961601. The next prime is 21961627. The reversal of 21961610 is 1616912.

It is a self number, because there is not a number n which added to its sum of digits gives 21961610.

It is an unprimeable number.

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, 3947 + ... + 7713.

It is an arithmetic number, because the mean of its divisors is an integer number (1373436).

Almost surely, 2^21961610 is an apocalyptic number.

21961610 is an abundant number, since it is smaller than the sum of its proper divisors (21988342).

21961610 is a wasteful number, since it uses less digits than its factorization.

21961610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3838.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 21961610 is about 4686.3215852094. The cubic root of 21961610 is about 280.0408528827.

The spelling of 21961610 in words is "twenty-one million, nine hundred sixty-one thousand, six hundred ten".