661501425 has 24 divisors (see below), whose sum is σ = 1177813504. Its totient is φ = 325661760.

The previous prime is 661501411. The next prime is 661501441. The reversal of 661501425 is 524105166.

It is not a de Polignac number, because 661501425 - 2⁶ = 661501361 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661501392 and 661501401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 338257 + ... + 340206.

Almost surely, 2^661501425 is an apocalyptic number.

661501425 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

661501425 is a deficient number, since it is larger than the sum of its proper divisors (516312079).

661501425 is a wasteful number, since it uses less digits than its factorization.

661501425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678489 (or 678484 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 661501425 is about 25719.6700017710. The cubic root of 661501425 is about 871.3184856970.

The spelling of 661501425 in words is "six hundred sixty-one million, five hundred one thousand, four hundred twenty-five".