21515452102054 has 4 divisors (see below), whose sum is σ = 32273178153084. Its totient is φ = 10757726051026.

The previous prime is 21515452102051. The next prime is 21515452102097. The reversal of 21515452102054 is 45020125451512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515452102051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5378863025512 + ... + 5378863025515.

It is an arithmetic number, because the mean of its divisors is an integer number (8068294538271).

Almost surely, 2^{21515452102054} is an apocalyptic number.

21515452102054 is a deficient number, since it is larger than the sum of its proper divisors (10757726051030).

21515452102054 is a wasteful number, since it uses less digits than its factorization.

21515452102054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10757726051029.

The product of its (nonzero) digits is 80000, while the sum is 37.

Adding to 21515452102054 its reverse (45020125451512), we get a palindrome (66535577553566).

The spelling of 21515452102054 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fifty-two million, one hundred two thousand, fifty-four".