1980856646 has 16 divisors (see below), whose sum is σ = 3101601888. Its totient is φ = 947020800.

The previous prime is 1980856637. The next prime is 1980856649. The reversal of 1980856646 is 6466580891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1980856649) 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, 156806 + ... + 168966.

It is an arithmetic number, because the mean of its divisors is an integer number (193850118).

Almost surely, 2^1980856646 is an apocalyptic number.

1980856646 is a deficient number, since it is larger than the sum of its proper divisors (1120745242).

1980856646 is a wasteful number, since it uses less digits than its factorization.

1980856646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15727.

The product of its (nonzero) digits is 2488320, while the sum is 53.

The square root of 1980856646 is about 44506.8157252347. The cubic root of 1980856646 is about 1255.8883032339. Note that the first 3 decimals are identical.

The spelling of 1980856646 in words is "one billion, nine hundred eighty million, eight hundred fifty-six thousand, six hundred forty-six".