21980856678 has 64 divisors (see below), whose sum is σ = 48378021120. Its totient is φ = 6602803200.

The previous prime is 21980856649. The next prime is 21980856713. The reversal of 21980856678 is 87665808912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3978558 + ... + 3984078.

It is an arithmetic number, because the mean of its divisors is an integer number (755906580).

Almost surely, 2^21980856678 is an apocalyptic number.

21980856678 is an abundant number, since it is smaller than the sum of its proper divisors (26397164442).

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

21980856678 is a wasteful number, since it uses less digits than its factorization.

21980856678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6053.

The product of its (nonzero) digits is 11612160, while the sum is 60.

The spelling of 21980856678 in words is "twenty-one billion, nine hundred eighty million, eight hundred fifty-six thousand, six hundred seventy-eight".