55142640 has 240 divisors, whose sum is σ = 221369760. Its totient is φ = 12579840.

The previous prime is 55142629. The next prime is 55142651. The reversal of 55142640 is 4624155.

55142640 is a `hidden beast` number, since 5 + 5 + 14 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (55142629) and next prime (55142651).

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 105580 + ... + 106100.

It is an arithmetic number, because the mean of its divisors is an integer number (922374).

Almost surely, 2^55142640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55142640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110684880).

55142640 is an abundant number, since it is smaller than the sum of its proper divisors (166227120).

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

55142640 is a wasteful number, since it uses less digits than its factorization.

55142640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557 (or 538 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 55142640 is about 7425.8090468312. The cubic root of 55142640 is about 380.6237217555.

Adding to 55142640 its reverse (4624155), we get a palindrome (59766795).

The spelling of 55142640 in words is "fifty-five million, one hundred forty-two thousand, six hundred forty".