425403661 has 2 divisors, whose sum is σ = 425403662. Its totient is φ = 425403660.

The previous prime is 425403647. The next prime is 425403701. The reversal of 425403661 is 166304524.

425403661 = T₁₆₈₃₉ + T₁₆₈₄₀ + T₁₆₈₄₁.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 416935561 + 8468100 = 20419^2 + 2910^2 .

It is a cyclic number.

It is not a de Polignac number, because 425403661 - 2²⁷ = 291185933 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 (425403061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 212701830 + 212701831.

It is an arithmetic number, because the mean of its divisors is an integer number (212701831).

Almost surely, 2^425403661 is an apocalyptic number.

425403661 is the 16841-st centered triangular number.

It is an amenable number.

425403661 is a deficient number, since it is larger than the sum of its proper divisors (1).

425403661 is an equidigital number, since it uses as much as digits as its factorization.

425403661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 425403661 is about 20625.3160218213. The cubic root of 425403661 is about 752.0852552777.

The spelling of 425403661 in words is "four hundred twenty-five million, four hundred three thousand, six hundred sixty-one".