21131356140 has 60 divisors (see below), whose sum is σ = 66289851936. Its totient is φ = 5635027872.

The previous prime is 21131356123. The next prime is 21131356187. The reversal of 21131356140 is 4165313112.

It is a happy number.

21131356140 is a `hidden beast` number, since 2 + 1 + 13 + 1 + 35 + 614 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6520404 + ... + 6523643.

Almost surely, 2^21131356140 is an apocalyptic number.

21131356140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131356140 is an abundant number, since it is smaller than the sum of its proper divisors (45158495796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21131356140 is a wasteful number, since it uses less digits than its factorization.

21131356140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13044068 (or 13044057 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

Adding to 21131356140 its reverse (4165313112), we get a palindrome (25296669252).

The spelling of 21131356140 in words is "twenty-one billion, one hundred thirty-one million, three hundred fifty-six thousand, one hundred forty".