21151315042431 has 16 divisors (see below), whose sum is σ = 32287823234304. Its totient is φ = 12064997764224.

The previous prime is 21151315042423. The next prime is 21151315042439. The reversal of 21151315042431 is 13424051315112.

It is an interprime number because it is at equal distance from previous prime (21151315042423) and next prime (21151315042439).

It is not a de Polignac number, because 21151315042431 - 2³ = 21151315042423 is a prime.

It is a super-2 number, since 2×21151315042431² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21151315042392 and 21151315042401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151315042439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 894486826 + ... + 894510471.

It is an arithmetic number, because the mean of its divisors is an integer number (2017988952144).

Almost surely, 2^{21151315042431} is an apocalyptic number.

21151315042431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21151315042431 is a deficient number, since it is larger than the sum of its proper divisors (11136508191873).

21151315042431 is a wasteful number, since it uses less digits than its factorization.

21151315042431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788997870.

The product of its (nonzero) digits is 14400, while the sum is 33.

Adding to 21151315042431 its reverse (13424051315112), we get a palindrome (34575366357543).

The spelling of 21151315042431 in words is "twenty-one trillion, one hundred fifty-one billion, three hundred fifteen million, forty-two thousand, four hundred thirty-one".