18936651456989 has 16 divisors (see below), whose sum is σ = 23311317688320. Its totient is φ = 15024872720880.

The previous prime is 18936651456979. The next prime is 18936651457001. The reversal of 18936651456989 is 98965415663981.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 18936651456989 - 2⁴⁴ = 1344465412573 is a prime.

It is a super-2 number, since 2×18936651456989² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18936651456979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1897074899 + ... + 1897084880.

It is an arithmetic number, because the mean of its divisors is an integer number (1456957355520).

Almost surely, 2^{18936651456989} is an apocalyptic number.

It is an amenable number.

18936651456989 is a deficient number, since it is larger than the sum of its proper divisors (4374666231331).

18936651456989 is a wasteful number, since it uses less digits than its factorization.

18936651456989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3794159840.

The product of its digits is 3023308800, while the sum is 80.

The spelling of 18936651456989 in words is "eighteen trillion, nine hundred thirty-six billion, six hundred fifty-one million, four hundred fifty-six thousand, nine hundred eighty-nine".