51111432540 has 180 divisors, whose sum is σ = 186516453816. Its totient is φ = 11682595008.

The previous prime is 51111432529. The next prime is 51111432599. The reversal of 51111432540 is 4523411115.

51111432540 is a `hidden beast` number, since 5 + 1 + 1 + 114 + 3 + 2 + 540 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×51111432540² (a number of 22 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 242562 + ... + 401321.

Almost surely, 2^51111432540 is an apocalyptic number.

It is an amenable number.

51111432540 is an abundant number, since it is smaller than the sum of its proper divisors (135405021276).

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

51111432540 is a wasteful number, since it uses less digits than its factorization.

51111432540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643918 (or 643900 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 51111432540 its reverse (4523411115), we get a palindrome (55634843655).

The spelling of 51111432540 in words is "fifty-one billion, one hundred eleven million, four hundred thirty-two thousand, five hundred forty".