20251220455 has 4 divisors (see below), whose sum is σ = 24301464552. Its totient is φ = 16200976360.

The previous prime is 20251220453. The next prime is 20251220459. The reversal of 20251220455 is 55402215202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55402215202 = 2 ⋅27701107601.

It is not a de Polignac number, because 20251220455 - 2¹ = 20251220453 is a prime.

It is a super-2 number, since 2×20251220455² (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 (20251220453) 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, 2025122041 + ... + 2025122050.

It is an arithmetic number, because the mean of its divisors is an integer number (6075366138).

Almost surely, 2^20251220455 is an apocalyptic number.

20251220455 is a deficient number, since it is larger than the sum of its proper divisors (4050244097).

20251220455 is an equidigital number, since it uses as much as digits as its factorization.

20251220455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4050244096.

The product of its (nonzero) digits is 8000, while the sum is 28.

Adding to 20251220455 its reverse (55402215202), we get a palindrome (75653435657).

The spelling of 20251220455 in words is "twenty billion, two hundred fifty-one million, two hundred twenty thousand, four hundred fifty-five".