55721047 has 2 divisors, whose sum is σ = 55721048. Its totient is φ = 55721046.

The previous prime is 55721033. The next prime is 55721059. The reversal of 55721047 is 74012755.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55721047 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55722047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860523 + 27860524.

It is an arithmetic number, because the mean of its divisors is an integer number (27860524).

Almost surely, 2^55721047 is an apocalyptic number.

55721047 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721047 is an equidigital number, since it uses as much as digits as its factorization.

55721047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9800, while the sum is 31.

The square root of 55721047 is about 7464.6531734569. The cubic root of 55721047 is about 381.9499194235.

The spelling of 55721047 in words is "fifty-five million, seven hundred twenty-one thousand, forty-seven".