1621612155 has 16 divisors (see below), whose sum is σ = 2595373344. Its totient is φ = 864595200.

The previous prime is 1621612151. The next prime is 1621612163. The reversal of 1621612155 is 5512161261.

It is not a de Polignac number, because 1621612155 - 2² = 1621612151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1621612151) 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, 40455 + ... + 69855.

It is an arithmetic number, because the mean of its divisors is an integer number (162210834).

Almost surely, 2^1621612155 is an apocalyptic number.

1621612155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1621612155 is a deficient number, since it is larger than the sum of its proper divisors (973761189).

1621612155 is a wasteful number, since it uses less digits than its factorization.

1621612155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33086.

The product of its digits is 3600, while the sum is 30.

The square root of 1621612155 is about 40269.2457714321. The cubic root of 1621612155 is about 1174.8497541405.

The spelling of 1621612155 in words is "one billion, six hundred twenty-one million, six hundred twelve thousand, one hundred fifty-five".