21121256162 has 16 divisors (see below), whose sum is σ = 32890199040. Its totient is φ = 10160430672.

The previous prime is 21121256131. The next prime is 21121256209. The reversal of 21121256162 is 26165212112.

It is a super-2 number, since 2×21121256162² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 626978 + ... + 659805.

It is an arithmetic number, because the mean of its divisors is an integer number (2055637440).

Almost surely, 2^21121256162 is an apocalyptic number.

21121256162 is a deficient number, since it is larger than the sum of its proper divisors (11768942878).

21121256162 is a wasteful number, since it uses less digits than its factorization.

21121256162 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287097.

The product of its digits is 2880, while the sum is 29.

Adding to 21121256162 its reverse (26165212112), we get a palindrome (47286468274).

The spelling of 21121256162 in words is "twenty-one billion, one hundred twenty-one million, two hundred fifty-six thousand, one hundred sixty-two".