71421557 has 4 divisors (see below), whose sum is σ = 71454336. Its totient is φ = 71388780.

The previous prime is 71421541. The next prime is 71421599. The reversal of 71421557 is 75512417.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75512417 = 67 ⋅1127051.

It is a cyclic number.

It is not a de Polignac number, because 71421557 - 2⁴ = 71421541 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 (71423557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12869 + ... + 17562.

It is an arithmetic number, because the mean of its divisors is an integer number (17863584).

Almost surely, 2^71421557 is an apocalyptic number.

It is an amenable number.

71421557 is a deficient number, since it is larger than the sum of its proper divisors (32779).

71421557 is a wasteful number, since it uses less digits than its factorization.

71421557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32778.

The product of its digits is 9800, while the sum is 32.

The square root of 71421557 is about 8451.1275579061. The cubic root of 71421557 is about 414.8996844676.

The spelling of 71421557 in words is "seventy-one million, four hundred twenty-one thousand, five hundred fifty-seven".