18951221231207 has 8 divisors (see below), whose sum is σ = 20134568690400. Its totient is φ = 17803197576864.

The previous prime is 18951221231197. The next prime is 18951221231219. The reversal of 18951221231207 is 70213212215981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18951221231207 - 2¹² = 18951221227111 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 (18951221261207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8830950107 + ... + 8830952252.

It is an arithmetic number, because the mean of its divisors is an integer number (2516821086300).

Almost surely, 2^{18951221231207} is an apocalyptic number.

18951221231207 is a deficient number, since it is larger than the sum of its proper divisors (1183347459193).

18951221231207 is a wasteful number, since it uses less digits than its factorization.

18951221231207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17661902425.

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 18951221231207 in words is "eighteen trillion, nine hundred fifty-one billion, two hundred twenty-one million, two hundred thirty-one thousand, two hundred seven".