55331640 has 256 divisors, whose sum is σ = 227404800. Its totient is φ = 11653632.

The previous prime is 55331611. The next prime is 55331657. The reversal of 55331640 is 4613355.

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 63 ways as a sum of consecutive naturals, for example, 97999 + ... + 98561.

It is an arithmetic number, because the mean of its divisors is an integer number (888300).

Almost surely, 2^55331640 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 55331640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113702400).

55331640 is an abundant number, since it is smaller than the sum of its proper divisors (172073160).

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

55331640 is a wasteful number, since it uses less digits than its factorization.

55331640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 55331640 is about 7438.5240471481. The cubic root of 55331640 is about 381.0580852604.

Adding to 55331640 its reverse (4613355), we get a palindrome (59944995).

The spelling of 55331640 in words is "fifty-five million, three hundred thirty-one thousand, six hundred forty".