1657155961 has 8 divisors (see below), whose sum is σ = 1729473480. Its totient is φ = 1585850112.

The previous prime is 1657155953. The next prime is 1657155967. The reversal of 1657155961 is 1695517561.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 58675600 + 1598480361 = 7660^2 + 39981^2 .

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 1657155961 - 2³ = 1657155953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1657155967) 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, 249570 + ... + 256123.

It is an arithmetic number, because the mean of its divisors is an integer number (216184185).

Almost surely, 2^1657155961 is an apocalyptic number.

It is an amenable number.

1657155961 is a deficient number, since it is larger than the sum of its proper divisors (72317519).

1657155961 is a wasteful number, since it uses less digits than its factorization.

1657155961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505835.

The product of its digits is 283500, while the sum is 46.

The square root of 1657155961 is about 40708.1805169428. The cubic root of 1657155961 is about 1183.3715603776.

The spelling of 1657155961 in words is "one billion, six hundred fifty-seven million, one hundred fifty-five thousand, nine hundred sixty-one".