21151231314321 has 32 divisors (see below), whose sum is σ = 29873160523008. Its totient is φ = 13265762918400.

The previous prime is 21151231314209. The next prime is 21151231314337. The reversal of 21151231314321 is 12341313215112.

It is a happy number.

It is not a de Polignac number, because 21151231314321 - 2¹³ = 21151231306129 is a prime.

It is a super-2 number, since 2×21151231314321² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21151231314821) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1939940556 + ... + 1939951458.

It is an arithmetic number, because the mean of its divisors is an integer number (933536266344).

Almost surely, 2^{21151231314321} is an apocalyptic number.

It is an amenable number.

21151231314321 is a deficient number, since it is larger than the sum of its proper divisors (8721929208687).

21151231314321 is a wasteful number, since it uses less digits than its factorization.

21151231314321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23481.

The product of its digits is 4320, while the sum is 30.

Adding to 21151231314321 its reverse (12341313215112), we get a palindrome (33492544529433).

The spelling of 21151231314321 in words is "twenty-one trillion, one hundred fifty-one billion, two hundred thirty-one million, three hundred fourteen thousand, three hundred twenty-one".