55780725 has 96 divisors (see below), whose sum is σ = 123992064. Its totient is φ = 21369600.

The previous prime is 55780721. The next prime is 55780729. The reversal of 55780725 is 52708755.

It is an interprime number because it is at equal distance from previous prime (55780721) and next prime (55780729).

It is not a de Polignac number, because 55780725 - 2² = 55780721 is a prime.

It is a super-2 number, since 2×55780725² = 6222978563051250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55780721) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 74704 + ... + 75446.

It is an arithmetic number, because the mean of its divisors is an integer number (1291584).

Almost surely, 2^55780725 is an apocalyptic number.

55780725 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

55780725 is an abundant number, since it is smaller than the sum of its proper divisors (68211339).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55780725 is a wasteful number, since it uses less digits than its factorization.

55780725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787 (or 782 counting only the distinct ones).

The product of its (nonzero) digits is 98000, while the sum is 39.

The square root of 55780725 is about 7468.6494763110. The cubic root of 55780725 is about 382.0862286268.

The spelling of 55780725 in words is "fifty-five million, seven hundred eighty thousand, seven hundred twenty-five".