20261691878 has 8 divisors (see below), whose sum is σ = 31213957872. Its totient is φ = 9857039256.

The previous prime is 20261691871. The next prime is 20261691929. The reversal of 20261691878 is 87819616202.

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

It is a super-2 number, since 2×20261691878² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20261691871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136903250 + ... + 136903397.

It is an arithmetic number, because the mean of its divisors is an integer number (3901744734).

Almost surely, 2^20261691878 is an apocalyptic number.

20261691878 is a deficient number, since it is larger than the sum of its proper divisors (10952265994).

20261691878 is a wasteful number, since it uses less digits than its factorization.

20261691878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273806686.

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 20261691878 in words is "twenty billion, two hundred sixty-one million, six hundred ninety-one thousand, eight hundred seventy-eight".