21772240394 has 4 divisors (see below), whose sum is σ = 32658360594. Its totient is φ = 10886120196.

The previous prime is 21772240393. The next prime is 21772240403. The reversal of 21772240394 is 49304227712.

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

It can be written as a sum of positive squares in only one way, i.e., 17745703369 + 4026537025 = 133213^2 + 63455^2 .

It is not an unprimeable number, because it can be changed into a prime (21772240393) by changing a digit.

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, 5443060097 + ... + 5443060100.

Almost surely, 2^21772240394 is an apocalyptic number.

21772240394 is a deficient number, since it is larger than the sum of its proper divisors (10886120200).

21772240394 is a wasteful number, since it uses less digits than its factorization.

21772240394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10886120199.

The product of its (nonzero) digits is 169344, while the sum is 41.

The spelling of 21772240394 in words is "twenty-one billion, seven hundred seventy-two million, two hundred forty thousand, three hundred ninety-four".