21978107377989 has 8 divisors (see below), whose sum is σ = 33490449337920. Its totient is φ = 12558918501696.

The previous prime is 21978107377987. The next prime is 21978107378047. The reversal of 21978107377989 is 98977370187912.

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

It is not a de Polignac number, because 21978107377989 - 2¹ = 21978107377987 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21978107377987) 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, 523288270884 + ... + 523288270925.

It is an arithmetic number, because the mean of its divisors is an integer number (4186306167240).

Almost surely, 2^{21978107377989} is an apocalyptic number.

It is an amenable number.

21978107377989 is a deficient number, since it is larger than the sum of its proper divisors (11512341959931).

21978107377989 is a wasteful number, since it uses less digits than its factorization.

21978107377989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046576541819.

The product of its (nonzero) digits is 672126336, while the sum is 78.

The spelling of 21978107377989 in words is "twenty-one trillion, nine hundred seventy-eight billion, one hundred seven million, three hundred seventy-seven thousand, nine hundred eighty-nine".