21261862 has 16 divisors (see below), whose sum is σ = 32804352. Its totient is φ = 10329280.

The previous prime is 21261839. The next prime is 21261869. The reversal of 21261862 is 26816212.

It is a super-4 number, since 4×21261862⁴ (a number of 30 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21261862.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261869) 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, 31068 + ... + 31744.

It is an arithmetic number, because the mean of its divisors is an integer number (2050272).

Almost surely, 2^21261862 is an apocalyptic number.

21261862 is a deficient number, since it is larger than the sum of its proper divisors (11542490).

21261862 is a wasteful number, since it uses less digits than its factorization.

21261862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103.

The product of its digits is 2304, while the sum is 28.

The square root of 21261862 is about 4611.0586636910. The cubic root of 21261862 is about 277.0344416244.

The spelling of 21261862 in words is "twenty-one million, two hundred sixty-one thousand, eight hundred sixty-two".