55621940 has 24 divisors (see below), whose sum is σ = 127425312. Its totient is φ = 20226080.

The previous prime is 55621939. The next prime is 55621991. The reversal of 55621940 is 4912655.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 55621897 and 55621906.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126194 + ... + 126633.

It is an arithmetic number, because the mean of its divisors is an integer number (5309388).

Almost surely, 2^55621940 is an apocalyptic number.

It is an amenable number.

55621940 is an abundant number, since it is smaller than the sum of its proper divisors (71803372).

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

55621940 is a wasteful number, since it uses less digits than its factorization.

55621940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252847 (or 252845 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 55621940 is about 7458.0117994007. The cubic root of 55621940 is about 381.7233361271.

The spelling of 55621940 in words is "fifty-five million, six hundred twenty-one thousand, nine hundred forty".