19950357421 has 4 divisors (see below), whose sum is σ = 19953755644. Its totient is φ = 19946959200.

The previous prime is 19950357419. The next prime is 19950357433. The reversal of 19950357421 is 12475305991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12475305991 = 1871 ⋅6667721.

It can be written as a sum of positive squares in 2 ways, for example, as 16030345321 + 3920012100 = 126611^2 + 62610^2 .

It is a cyclic number.

It is not a de Polignac number, because 19950357421 - 2¹ = 19950357419 is a prime.

It is a super-2 number, since 2×19950357421² (a number of 21 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 (19950357451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1690290 + ... + 1702051.

It is an arithmetic number, because the mean of its divisors is an integer number (4988438911).

Almost surely, 2^19950357421 is an apocalyptic number.

It is an amenable number.

19950357421 is a deficient number, since it is larger than the sum of its proper divisors (3398223).

19950357421 is an equidigital number, since it uses as much as digits as its factorization.

19950357421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3398222.

The product of its (nonzero) digits is 340200, while the sum is 46.

The spelling of 19950357421 in words is "nineteen billion, nine hundred fifty million, three hundred fifty-seven thousand, four hundred twenty-one".