615625421 has 2 divisors, whose sum is σ = 615625422. Its totient is φ = 615625420.

The previous prime is 615625397. The next prime is 615625447. The reversal of 615625421 is 124526516.

615625421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 366301321 + 249324100 = 19139^2 + 15790^2 .

It is a cyclic number.

It is not a de Polignac number, because 615625421 - 2¹⁰ = 615624397 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (615625321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 307812710 + 307812711.

It is an arithmetic number, because the mean of its divisors is an integer number (307812711).

Almost surely, 2^615625421 is an apocalyptic number.

It is an amenable number.

615625421 is a deficient number, since it is larger than the sum of its proper divisors (1).

615625421 is an equidigital number, since it uses as much as digits as its factorization.

615625421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 32.

The square root of 615625421 is about 24811.8000354670. The cubic root of 615625421 is about 850.6916727661.

The spelling of 615625421 in words is "six hundred fifteen million, six hundred twenty-five thousand, four hundred twenty-one".