20909345478 has 32 divisors (see below), whose sum is σ = 47797102080. Its totient is φ = 5973559680.

The previous prime is 20909345411. The next prime is 20909345503. The reversal of 20909345478 is 87454390902.

It is a self number, because there is not a number n which added to its sum of digits gives 20909345478.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 822823 + ... + 847853.

It is an arithmetic number, because the mean of its divisors is an integer number (1493659440).

Almost surely, 2^20909345478 is an apocalyptic number.

20909345478 is an abundant number, since it is smaller than the sum of its proper divisors (26887756602).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20909345478 is a wasteful number, since it uses less digits than its factorization.

20909345478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44932.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 20909345478 in words is "twenty billion, nine hundred nine million, three hundred forty-five thousand, four hundred seventy-eight".