620040991 has 4 divisors (see below), whose sum is σ = 635163984. Its totient is φ = 604918000.

The previous prime is 620040979. The next prime is 620041031. The reversal of 620040991 is 199040026.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 620040991 - 2¹³ = 620032799 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620040961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7561435 + ... + 7561516.

It is an arithmetic number, because the mean of its divisors is an integer number (158790996).

Almost surely, 2^620040991 is an apocalyptic number.

620040991 is a deficient number, since it is larger than the sum of its proper divisors (15122993).

620040991 is a wasteful number, since it uses less digits than its factorization.

620040991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15122992.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 620040991 is about 24900.6223014607. The cubic root of 620040991 is about 852.7206899052.

The spelling of 620040991 in words is "six hundred twenty million, forty thousand, nine hundred ninety-one".