21735091946 has 4 divisors (see below), whose sum is σ = 32602637922. Its totient is φ = 10867545972.

The previous prime is 21735091901. The next prime is 21735091949. The reversal of 21735091946 is 64919053712.

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., 21144358921 + 590733025 = 145411^2 + 24305^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21735091946.

It is not an unprimeable number, because it can be changed into a prime (21735091949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5433772985 + ... + 5433772988.

Almost surely, 2^21735091946 is an apocalyptic number.

21735091946 is a deficient number, since it is larger than the sum of its proper divisors (10867545976).

21735091946 is a wasteful number, since it uses less digits than its factorization.

21735091946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10867545975.

The product of its (nonzero) digits is 408240, while the sum is 47.

The spelling of 21735091946 in words is "twenty-one billion, seven hundred thirty-five million, ninety-one thousand, nine hundred forty-six".