721540037 has 2 divisors, whose sum is σ = 721540038. Its totient is φ = 721540036.

The previous prime is 721540019. The next prime is 721540049. The reversal of 721540037 is 730045127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 686125636 + 35414401 = 26194^2 + 5951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721540037 is a prime.

It is a super-2 number, since 2×721540037² = 1041240049987922738, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 721539991 and 721540009.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721540007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360770018 + 360770019.

It is an arithmetic number, because the mean of its divisors is an integer number (360770019).

Almost surely, 2^721540037 is an apocalyptic number.

It is an amenable number.

721540037 is a deficient number, since it is larger than the sum of its proper divisors (1).

721540037 is an equidigital number, since it uses as much as digits as its factorization.

721540037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 721540037 is about 26861.4972963162. The cubic root of 721540037 is about 896.9195247103.

The spelling of 721540037 in words is "seven hundred twenty-one million, five hundred forty thousand, thirty-seven".