21964232061 has 6 divisors (see below), whose sum is σ = 31726112990. Its totient is φ = 14642821368.

The previous prime is 21964232039. The next prime is 21964232107. The reversal of 21964232061 is 16023246912.

It is a happy number.

21964232061 is a `hidden beast` number, since 2 + 1 + 9 + 642 + 3 + 2 + 0 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20390126436 + 1574105625 = 142794^2 + 39675^2 .

It is not a de Polignac number, because 21964232061 - 2¹⁵ = 21964199293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21964232011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1220235106 + ... + 1220235123.

Almost surely, 2^21964232061 is an apocalyptic number.

It is an amenable number.

21964232061 is a deficient number, since it is larger than the sum of its proper divisors (9761880929).

21964232061 is a wasteful number, since it uses less digits than its factorization.

21964232061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440470235 (or 2440470232 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

Adding to 21964232061 its reverse (16023246912), we get a palindrome (37987478973).

The spelling of 21964232061 in words is "twenty-one billion, nine hundred sixty-four million, two hundred thirty-two thousand, sixty-one".