20515454 has 4 divisors (see below), whose sum is σ = 30773184. Its totient is φ = 10257726.

The previous prime is 20515393. The next prime is 20515463. The reversal of 20515454 is 45451502.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×20515454² = 841767705652232, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5128862 + ... + 5128865.

It is an arithmetic number, because the mean of its divisors is an integer number (7693296).

Almost surely, 2^20515454 is an apocalyptic number.

20515454 is a deficient number, since it is larger than the sum of its proper divisors (10257730).

20515454 is a wasteful number, since it uses less digits than its factorization.

20515454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10257729.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 20515454 is about 4529.3988563605. The cubic root of 20515454 is about 273.7539393246.

Adding to 20515454 its reverse (45451502), we get a palindrome (65966956).

The spelling of 20515454 in words is "twenty million, five hundred fifteen thousand, four hundred fifty-four".