21772317145 has 8 divisors (see below), whose sum is σ = 26271128520. Its totient is φ = 17321621760.

The previous prime is 21772317139. The next prime is 21772317167. The reversal of 21772317145 is 54171327712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 834516544 + 20937800601 = 28888^2 + 144699^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21772317145 - 2¹⁵ = 21772284377 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21772317098 and 21772317107.

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, 12028000 + ... + 12029809.

It is an arithmetic number, because the mean of its divisors is an integer number (3283891065).

Almost surely, 2^21772317145 is an apocalyptic number.

It is an amenable number.

21772317145 is a deficient number, since it is larger than the sum of its proper divisors (4498811375).

21772317145 is a wasteful number, since it uses less digits than its factorization.

21772317145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24057995.

The product of its digits is 82320, while the sum is 40.

The spelling of 21772317145 in words is "twenty-one billion, seven hundred seventy-two million, three hundred seventeen thousand, one hundred forty-five".