1655620989 has 16 divisors (see below), whose sum is σ = 2409549120. Its totient is φ = 1002834560.

The previous prime is 1655620949. The next prime is 1655620997. The reversal of 1655620989 is 9890265561.

It is a cyclic number.

It is not a de Polignac number, because 1655620989 - 2¹³ = 1655612797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1655620949) 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, 48577 + ... + 75305.

It is an arithmetic number, because the mean of its divisors is an integer number (150596820).

Almost surely, 2^1655620989 is an apocalyptic number.

It is an amenable number.

1655620989 is a deficient number, since it is larger than the sum of its proper divisors (753928131).

1655620989 is a wasteful number, since it uses less digits than its factorization.

1655620989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28620.

The product of its (nonzero) digits is 1166400, while the sum is 51.

The square root of 1655620989 is about 40689.3227886629. The cubic root of 1655620989 is about 1183.0060740906.

The spelling of 1655620989 in words is "one billion, six hundred fifty-five million, six hundred twenty thousand, nine hundred eighty-nine".