1661672151655 has 16 divisors (see below), whose sum is σ = 2004608424960. Its totient is φ = 1322282376352.

The previous prime is 1661672151593. The next prime is 1661672151719. The reversal of 1661672151655 is 5561512761661.

It is a cyclic number.

It is not a de Polignac number, because 1661672151655 - 2¹³ = 1661672143463 is a prime.

It is a super-2 number, since 2×1661672151655² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 276132 + ... + 1843798.

It is an arithmetic number, because the mean of its divisors is an integer number (125288026560).

Almost surely, 2^{1661672151655} is an apocalyptic number.

1661672151655 is a deficient number, since it is larger than the sum of its proper divisors (342936273305).

1661672151655 is a wasteful number, since it uses less digits than its factorization.

1661672151655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568798.

The product of its digits is 2268000, while the sum is 52.

The spelling of 1661672151655 in words is "one trillion, six hundred sixty-one billion, six hundred seventy-two million, one hundred fifty-one thousand, six hundred fifty-five".