21654501983 has 2 divisors, whose sum is σ = 21654501984. Its totient is φ = 21654501982.

The previous prime is 21654501917. The next prime is 21654502019. The reversal of 21654501983 is 38910545612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21654501983 - 2¹⁴ = 21654485599 is a prime.

It is a super-2 number, since 2×21654501983² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21654501683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827250991 + 10827250992.

It is an arithmetic number, because the mean of its divisors is an integer number (10827250992).

Almost surely, 2^21654501983 is an apocalyptic number.

21654501983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21654501983 is an equidigital number, since it uses as much as digits as its factorization.

21654501983 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 44.

The spelling of 21654501983 in words is "twenty-one billion, six hundred fifty-four million, five hundred one thousand, nine hundred eighty-three".