1988601961 has 2 divisors, whose sum is σ = 1988601962. Its totient is φ = 1988601960.

The previous prime is 1988601943. The next prime is 1988601973. The reversal of 1988601961 is 1691068891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1146499600 + 842102361 = 33860^2 + 29019^2 .

It is an emirp because it is prime and its reverse (1691068891) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1961098861 and 1688901691.

It is a cyclic number.

It is not a de Polignac number, because 1988601961 - 2¹¹ = 1988599913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1988601661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994300980 + 994300981.

It is an arithmetic number, because the mean of its divisors is an integer number (994300981).

Almost surely, 2^1988601961 is an apocalyptic number.

It is an amenable number.

1988601961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988601961 is an equidigital number, since it uses as much as digits as its factorization.

1988601961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 49.

The square root of 1988601961 is about 44593.7435185700. The cubic root of 1988601961 is about 1257.5230504834.

The spelling of 1988601961 in words is "one billion, nine hundred eighty-eight million, six hundred one thousand, nine hundred sixty-one".