1555420725 has 60 divisors (see below), whose sum is σ = 2948346016. Its totient is φ = 810220320.

The previous prime is 1555420721. The next prime is 1555420751. The reversal of 1555420725 is 5270245551.

1555420725 is a `hidden beast` number, since 15 + 554 + 20 + 72 + 5 = 666.

It is not a de Polignac number, because 1555420725 - 2² = 1555420721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1555420725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1555420721) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 78144 + ... + 96006.

Almost surely, 2^1555420725 is an apocalyptic number.

1555420725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1555420725 is a deficient number, since it is larger than the sum of its proper divisors (1392925291).

1555420725 is a wasteful number, since it uses less digits than its factorization.

1555420725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17928 (or 17914 counting only the distinct ones).

The product of its (nonzero) digits is 70000, while the sum is 36.

The square root of 1555420725 is about 39438.8225610248. The cubic root of 1555420725 is about 1158.6420705708.

The spelling of 1555420725 in words is "one billion, five hundred fifty-five million, four hundred twenty thousand, seven hundred twenty-five".