1256170542421 has 8 divisors (see below), whose sum is σ = 1274219071488. Its totient is φ = 1238131902000.

The previous prime is 1256170542409. The next prime is 1256170542457. The reversal of 1256170542421 is 1242450716521.

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 1256170542421 - 2²⁷ = 1256036324693 is a prime.

It is a super-3 number, since 3×1256170542421³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256170542461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2216085 + ... + 2724586.

It is an arithmetic number, because the mean of its divisors is an integer number (159277383936).

Almost surely, 2^{1256170542421} is an apocalyptic number.

It is an amenable number.

1256170542421 is a deficient number, since it is larger than the sum of its proper divisors (18048529067).

1256170542421 is an equidigital number, since it uses as much as digits as its factorization.

1256170542421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4944323.

The product of its (nonzero) digits is 134400, while the sum is 40.

The spelling of 1256170542421 in words is "one trillion, two hundred fifty-six billion, one hundred seventy million, five hundred forty-two thousand, four hundred twenty-one".