1025661555 has 16 divisors (see below), whose sum is σ = 1823398560. Its totient is φ = 547019424.

The previous prime is 1025661541. The next prime is 1025661583. The reversal of 1025661555 is 5551665201.

1025661555 is a `hidden beast` number, since 10 + 25 + 6 + 615 + 5 + 5 = 666.

It is not a de Polignac number, because 1025661555 - 2⁵ = 1025661523 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3798612 + ... + 3798881.

It is an arithmetic number, because the mean of its divisors is an integer number (113962410).

Almost surely, 2^1025661555 is an apocalyptic number.

1025661555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1025661555 is a deficient number, since it is larger than the sum of its proper divisors (797737005).

1025661555 is an equidigital number, since it uses as much as digits as its factorization.

1025661555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7597507 (or 7597501 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

The square root of 1025661555 is about 32025.9512739278. The cubic root of 1025661555 is about 1008.4817088913.

The spelling of 1025661555 in words is "one billion, twenty-five million, six hundred sixty-one thousand, five hundred fifty-five".