20451155 has 8 divisors (see below), whose sum is σ = 24568272. Its totient is φ = 16343008.

The previous prime is 20451131. The next prime is 20451181. The reversal of 20451155 is 55115402.

It is a happy number.

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 20451155 - 2¹⁶ = 20385619 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20451155.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4784 + ... + 7986.

It is an arithmetic number, because the mean of its divisors is an integer number (3071034).

Almost surely, 2^20451155 is an apocalyptic number.

20451155 is a deficient number, since it is larger than the sum of its proper divisors (4117117).

20451155 is a wasteful number, since it uses less digits than its factorization.

20451155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4485.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 20451155 is about 4522.2953242795. The cubic root of 20451155 is about 273.4676425329.

Adding to 20451155 its reverse (55115402), we get a palindrome (75566557).

The spelling of 20451155 in words is "twenty million, four hundred fifty-one thousand, one hundred fifty-five".