20961410947 has 4 divisors (see below), whose sum is σ = 20961706480. Its totient is φ = 20961115416.

The previous prime is 20961410933. The next prime is 20961410963. The reversal of 20961410947 is 74901416902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(20961410947) divides (20961410947-1)³.

It is a cyclic number.

It is not a de Polignac number, because 20961410947 - 2¹¹ = 20961408899 is a prime.

It is a super-2 number, since 2×20961410947² (a number of 21 digits) contains 22 as substring.

It is a deceptive number, since it divides R_20961410946.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20961416947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29554 + ... + 206872.

It is an arithmetic number, because the mean of its divisors is an integer number (5240426620).

Almost surely, 2^20961410947 is an apocalyptic number.

20961410947 is the 118213-rd pentagonal number.

20961410947 is a deficient number, since it is larger than the sum of its proper divisors (295533).

20961410947 is a wasteful number, since it uses less digits than its factorization.

20961410947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295532.

The product of its (nonzero) digits is 108864, while the sum is 43.

The spelling of 20961410947 in words is "twenty billion, nine hundred sixty-one million, four hundred ten thousand, nine hundred forty-seven".