1947997491 has 16 divisors (see below), whose sum is σ = 2860965120. Its totient is φ = 1169140320.

The previous prime is 1947997433. The next prime is 1947997507.

1947997491 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1947997491 - 2⁶ = 1947997427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1947997421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 283156 + ... + 289953.

It is an arithmetic number, because the mean of its divisors is an integer number (178810320).

Almost surely, 2^1947997491 is an apocalyptic number.

1947997491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1947997491 is a deficient number, since it is larger than the sum of its proper divisors (912967629).

1947997491 is a wasteful number, since it uses less digits than its factorization.

1947997491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573226.

The product of its digits is 5143824, while the sum is 60.

The square root of 1947997491 is about 44136.1245580080. The cubic root of 1947997491 is about 1248.9051727760.

The spelling of 1947997491 in words is "one billion, nine hundred forty-seven million, nine hundred ninety-seven thousand, four hundred ninety-one".