21152740609 has 32 divisors (see below), whose sum is σ = 28426293504. Its totient is φ = 15201146880.

The previous prime is 21152740607. The next prime is 21152740667. The reversal of 21152740609 is 90604725112.

It is a cyclic number.

It is not a de Polignac number, because 21152740609 - 2¹ = 21152740607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21152740607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1185337 + ... + 1203049.

It is an arithmetic number, because the mean of its divisors is an integer number (888321672).

Almost surely, 2^21152740609 is an apocalyptic number.

It is an amenable number.

21152740609 is a deficient number, since it is larger than the sum of its proper divisors (7273552895).

21152740609 is a wasteful number, since it uses less digits than its factorization.

21152740609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18937.

The product of its (nonzero) digits is 30240, while the sum is 37.

The spelling of 21152740609 in words is "twenty-one billion, one hundred fifty-two million, seven hundred forty thousand, six hundred nine".