53721637 has 2 divisors, whose sum is σ = 53721638. Its totient is φ = 53721636.

The previous prime is 53721599. The next prime is 53721641. The reversal of 53721637 is 73612735.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53714241 + 7396 = 7329^2 + 86^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-53721637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53721677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26860818 + 26860819.

It is an arithmetic number, because the mean of its divisors is an integer number (26860819).

Almost surely, 2^53721637 is an apocalyptic number.

It is an amenable number.

53721637 is a deficient number, since it is larger than the sum of its proper divisors (1).

53721637 is an equidigital number, since it uses as much as digits as its factorization.

53721637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26460, while the sum is 34.

The square root of 53721637 is about 7329.5045535152. The cubic root of 53721637 is about 377.3257228096.

The spelling of 53721637 in words is "fifty-three million, seven hundred twenty-one thousand, six hundred thirty-seven".