1981986501 has 32 divisors (see below), whose sum is σ = 3040750080. Its totient is φ = 1135684800.

The previous prime is 1981986499. The next prime is 1981986533. The reversal of 1981986501 is 1056891891.

It is not a de Polignac number, because 1981986501 - 2¹ = 1981986499 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981986551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 336286 + ... + 342128.

It is an arithmetic number, because the mean of its divisors is an integer number (95023440).

Almost surely, 2^1981986501 is an apocalyptic number.

1981986501 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1981986501 is a deficient number, since it is larger than the sum of its proper divisors (1058763579).

1981986501 is a wasteful number, since it uses less digits than its factorization.

1981986501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6417.

The product of its (nonzero) digits is 155520, while the sum is 48.

The square root of 1981986501 is about 44519.5069716636. The cubic root of 1981986501 is about 1256.1270386617.

The spelling of 1981986501 in words is "one billion, nine hundred eighty-one million, nine hundred eighty-six thousand, five hundred one".