21576471507764 has 6 divisors (see below), whose sum is σ = 37758825138594. Its totient is φ = 10788235753880.

The previous prime is 21576471507739. The next prime is 21576471507779. The reversal of 21576471507764 is 46770517467512.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12652462420900 + 8924009086864 = 3557030^2 + 2987308^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21576471507697 and 21576471507706.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2697058938467 + ... + 2697058938474.

It is an arithmetic number, because the mean of its divisors is an integer number (6293137523099).

Almost surely, 2^{21576471507764} is an apocalyptic number.

It is an amenable number.

21576471507764 is a deficient number, since it is larger than the sum of its proper divisors (16182353630830).

21576471507764 is a wasteful number, since it uses less digits than its factorization.

21576471507764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5394117876945 (or 5394117876943 counting only the distinct ones).

The product of its (nonzero) digits is 69148800, while the sum is 62.

The spelling of 21576471507764 in words is "twenty-one trillion, five hundred seventy-six billion, four hundred seventy-one million, five hundred seven thousand, seven hundred sixty-four".