21860561149 has 24 divisors (see below), whose sum is σ = 26724385248. Its totient is φ = 17807156640.

The previous prime is 21860561143. The next prime is 21860561153. The reversal of 21860561149 is 94116506812.

It is not a de Polignac number, because 21860561149 - 2¹³ = 21860552957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21860561143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62247 + ... + 218164.

It is an arithmetic number, because the mean of its divisors is an integer number (1113516052).

Almost surely, 2^21860561149 is an apocalyptic number.

It is an amenable number.

21860561149 is a deficient number, since it is larger than the sum of its proper divisors (4863824099).

21860561149 is a wasteful number, since it uses less digits than its factorization.

21860561149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280505 (or 280498 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 43.

The spelling of 21860561149 in words is "twenty-one billion, eight hundred sixty million, five hundred sixty-one thousand, one hundred forty-nine".