620991390 has 16 divisors (see below), whose sum is σ = 1490379408. Its totient is φ = 165597696.

The previous prime is 620991389. The next prime is 620991391. The reversal of 620991390 is 93199026.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (620991389) and next prime (620991391).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620991391) 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, 10349827 + ... + 10349886.

It is an arithmetic number, because the mean of its divisors is an integer number (93148713).

Almost surely, 2^620991390 is an apocalyptic number.

620991390 is an abundant number, since it is smaller than the sum of its proper divisors (869388018).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

620991390 is a wasteful number, since it uses less digits than its factorization.

620991390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20699723.

The product of its (nonzero) digits is 26244, while the sum is 39.

The square root of 620991390 is about 24919.6988344562. The cubic root of 620991390 is about 853.1561509912.

The spelling of 620991390 in words is "six hundred twenty million, nine hundred ninety-one thousand, three hundred ninety".