71156421 has 32 divisors (see below), whose sum is σ = 120913920. Its totient is φ = 40513392.

The previous prime is 71156389. The next prime is 71156473. The reversal of 71156421 is 12465117.

71156421 = T₁₉₀ + T₁₉₁ + ... + T₇₅₆.

It is a happy number.

71156421 is a `hidden beast` number, since 7 + 1 + 15 + 642 + 1 = 666.

It is not a de Polignac number, because 71156421 - 2⁵ = 71156389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71156021) 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 31 ways as a sum of consecutive naturals, for example, 71896 + ... + 72878.

It is an arithmetic number, because the mean of its divisors is an integer number (3778560).

Almost surely, 2^71156421 is an apocalyptic number.

It is an amenable number.

71156421 is a deficient number, since it is larger than the sum of its proper divisors (49757499).

71156421 is a wasteful number, since it uses less digits than its factorization.

71156421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1382 (or 1376 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 71156421 is about 8435.4265452317. The cubic root of 71156421 is about 414.3856415031.

The spelling of 71156421 in words is "seventy-one million, one hundred fifty-six thousand, four hundred twenty-one".