2131756421 has 8 divisors (see below), whose sum is σ = 2145105888. Its totient is φ = 2118438000.

The previous prime is 2131756411. The next prime is 2131756427. The reversal of 2131756421 is 1246571312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2131756421 - 2¹⁰ = 2131755397 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 (2131756427) 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 7 ways as a sum of consecutive naturals, for example, 138491 + ... + 153111.

It is an arithmetic number, because the mean of its divisors is an integer number (268138236).

Almost surely, 2^2131756421 is an apocalyptic number.

It is an amenable number.

2131756421 is a deficient number, since it is larger than the sum of its proper divisors (13349467).

2131756421 is a wasteful number, since it uses less digits than its factorization.

2131756421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15523.

The product of its digits is 10080, while the sum is 32.

The square root of 2131756421 is about 46170.9478027038. The cubic root of 2131756421 is about 1287.0019154319.

The spelling of 2131756421 in words is "two billion, one hundred thirty-one million, seven hundred fifty-six thousand, four hundred twenty-one".