351405777421 has 4 divisors (see below), whose sum is σ = 351493043872. Its totient is φ = 351318510972.

The previous prime is 351405777413. The next prime is 351405777427. The reversal of 351405777421 is 124777504153.

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: 124777504153 = 29 ⋅4302672557.

It is a cyclic number.

It is not a de Polignac number, because 351405777421 - 2³ = 351405777413 is a prime.

It is a super-2 number, since 2×351405777421² (a number of 24 digits) contains 22 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 (351405777427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43627185 + ... + 43635238.

It is an arithmetic number, because the mean of its divisors is an integer number (87873260968).

Almost surely, 2^351405777421 is an apocalyptic number.

It is an amenable number.

351405777421 is a deficient number, since it is larger than the sum of its proper divisors (87266451).

351405777421 is an equidigital number, since it uses as much as digits as its factorization.

351405777421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87266450.

The product of its (nonzero) digits is 823200, while the sum is 46.

The spelling of 351405777421 in words is "three hundred fifty-one billion, four hundred five million, seven hundred seventy-seven thousand, four hundred twenty-one".