1551397871 has 4 divisors (see below), whose sum is σ = 1551882744. Its totient is φ = 1550913000.

The previous prime is 1551397867. The next prime is 1551397877. The reversal of 1551397871 is 1787931551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1551397871 - 2² = 1551397867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1551397877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237605 + ... + 244046.

It is an arithmetic number, because the mean of its divisors is an integer number (387970686).

Almost surely, 2^1551397871 is an apocalyptic number.

1551397871 is a deficient number, since it is larger than the sum of its proper divisors (484873).

1551397871 is an equidigital number, since it uses as much as digits as its factorization.

1551397871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484872.

The product of its digits is 264600, while the sum is 47.

The square root of 1551397871 is about 39387.7883486748. The cubic root of 1551397871 is about 1157.6423256239.

The spelling of 1551397871 in words is "one billion, five hundred fifty-one million, three hundred ninety-seven thousand, eight hundred seventy-one".