1257205551 has 16 divisors (see below), whose sum is σ = 1917129984. Its totient is φ = 717882624.

The previous prime is 1257205549. The next prime is 1257205567. The reversal of 1257205551 is 1555027521.

It is not a de Polignac number, because 1257205551 - 2¹ = 1257205549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257205451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8991 + ... + 50943.

It is an arithmetic number, because the mean of its divisors is an integer number (119820624).

Almost surely, 2^1257205551 is an apocalyptic number.

1257205551 is a deficient number, since it is larger than the sum of its proper divisors (659924433).

1257205551 is a wasteful number, since it uses less digits than its factorization.

1257205551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43390.

The product of its (nonzero) digits is 17500, while the sum is 33.

The square root of 1257205551 is about 35457.0945087157. The cubic root of 1257205551 is about 1079.2832323958.

The spelling of 1257205551 in words is "one billion, two hundred fifty-seven million, two hundred five thousand, five hundred fifty-one".