991969401 has 8 divisors (see below), whose sum is σ = 1324672704. Its totient is φ = 660289520.

The previous prime is 991969399. The next prime is 991969421. The reversal of 991969401 is 104969199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991969401 - 2¹ = 991969399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991969421) 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, 253590 + ... + 257471.

It is an arithmetic number, because the mean of its divisors is an integer number (165584088).

Almost surely, 2^991969401 is an apocalyptic number.

It is an amenable number.

991969401 is a deficient number, since it is larger than the sum of its proper divisors (332703303).

991969401 is a wasteful number, since it uses less digits than its factorization.

991969401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511711.

The product of its (nonzero) digits is 157464, while the sum is 48.

The square root of 991969401 is about 31495.5457326905. The cubic root of 991969401 is about 997.3159359122.

The spelling of 991969401 in words is "nine hundred ninety-one million, nine hundred sixty-nine thousand, four hundred one".